Download - Character Tables - MIT
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3D Aromaticity of Closo Polyhedral Borane Anions
5.03 Inorganic Chemistry
![Page 7: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/7.jpg)
Boron Clusters come of AgeRussell N. Grimes J. Chem. Educ. 2004, 81 657.
The stable existence of the neutral and polyhedral boraneshelped force a revolution in the way chemists think aboutcovalent bonding
Additionally, there are diverse areas of application exploitingtheir remarkable properties
Icosahedral B12H2−12 is water soluble and heat resistant: salts
survive temperatures above 810 ◦C without decomposition
B12H2−12 is arguably the most stable molecule in all of
chemistry
Its chemical inertness leads to very low toxicity in humans andsuitability for medical applications
5.03 Inorganic Chemistry
![Page 8: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/8.jpg)
Boron Clusters come of AgeRussell N. Grimes J. Chem. Educ. 2004, 81 657.
The stable existence of the neutral and polyhedral boraneshelped force a revolution in the way chemists think aboutcovalent bonding
Additionally, there are diverse areas of application exploitingtheir remarkable properties
Icosahedral B12H2−12 is water soluble and heat resistant: salts
survive temperatures above 810 ◦C without decomposition
B12H2−12 is arguably the most stable molecule in all of
chemistry
Its chemical inertness leads to very low toxicity in humans andsuitability for medical applications
5.03 Inorganic Chemistry
![Page 9: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/9.jpg)
Boron Clusters come of AgeRussell N. Grimes J. Chem. Educ. 2004, 81 657.
The stable existence of the neutral and polyhedral boraneshelped force a revolution in the way chemists think aboutcovalent bonding
Additionally, there are diverse areas of application exploitingtheir remarkable properties
Icosahedral B12H2−12 is water soluble and heat resistant: salts
survive temperatures above 810 ◦C without decomposition
B12H2−12 is arguably the most stable molecule in all of
chemistry
Its chemical inertness leads to very low toxicity in humans andsuitability for medical applications
5.03 Inorganic Chemistry
![Page 10: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/10.jpg)
Boron Clusters come of AgeRussell N. Grimes J. Chem. Educ. 2004, 81 657.
The stable existence of the neutral and polyhedral boraneshelped force a revolution in the way chemists think aboutcovalent bonding
Additionally, there are diverse areas of application exploitingtheir remarkable properties
Icosahedral B12H2−12 is water soluble and heat resistant: salts
survive temperatures above 810 ◦C without decomposition
B12H2−12 is arguably the most stable molecule in all of
chemistry
Its chemical inertness leads to very low toxicity in humans andsuitability for medical applications
5.03 Inorganic Chemistry
![Page 11: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/11.jpg)
Boron Clusters come of AgeRussell N. Grimes J. Chem. Educ. 2004, 81 657.
The stable existence of the neutral and polyhedral boraneshelped force a revolution in the way chemists think aboutcovalent bonding
Additionally, there are diverse areas of application exploitingtheir remarkable properties
Icosahedral B12H2−12 is water soluble and heat resistant: salts
survive temperatures above 810 ◦C without decomposition
B12H2−12 is arguably the most stable molecule in all of
chemistry
Its chemical inertness leads to very low toxicity in humans andsuitability for medical applications
5.03 Inorganic Chemistry
![Page 12: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/12.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
11B signals are more intense than those for 10B due to greaternatural abundance11B has a larger nuclear magnetic moment than 10B
NMR signal-to-noise increases with increasing nuclearmagnetic moment
Nuclear spin I in units of h/2π of 11B is 3/2 while that of 10Bis 3
The larger nuclear quadrupole moment of 10B gives it spectrathat are not as sharp as for 11B
5.03 Inorganic Chemistry
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Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
11B signals are more intense than those for 10B due to greaternatural abundance11B has a larger nuclear magnetic moment than 10B
NMR signal-to-noise increases with increasing nuclearmagnetic moment
Nuclear spin I in units of h/2π of 11B is 3/2 while that of 10Bis 3
The larger nuclear quadrupole moment of 10B gives it spectrathat are not as sharp as for 11B
5.03 Inorganic Chemistry
![Page 14: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/14.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
11B signals are more intense than those for 10B due to greaternatural abundance11B has a larger nuclear magnetic moment than 10B
NMR signal-to-noise increases with increasing nuclearmagnetic moment
Nuclear spin I in units of h/2π of 11B is 3/2 while that of 10Bis 3
The larger nuclear quadrupole moment of 10B gives it spectrathat are not as sharp as for 11B
5.03 Inorganic Chemistry
![Page 15: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/15.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
11B signals are more intense than those for 10B due to greaternatural abundance11B has a larger nuclear magnetic moment than 10B
NMR signal-to-noise increases with increasing nuclearmagnetic moment
Nuclear spin I in units of h/2π of 11B is 3/2 while that of 10Bis 3
The larger nuclear quadrupole moment of 10B gives it spectrathat are not as sharp as for 11B
5.03 Inorganic Chemistry
![Page 16: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/16.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
11B signals are more intense than those for 10B due to greaternatural abundance11B has a larger nuclear magnetic moment than 10B
NMR signal-to-noise increases with increasing nuclearmagnetic moment
Nuclear spin I in units of h/2π of 11B is 3/2 while that of 10Bis 3
The larger nuclear quadrupole moment of 10B gives it spectrathat are not as sharp as for 11B
5.03 Inorganic Chemistry
![Page 17: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/17.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 18: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/18.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 19: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/19.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 20: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/20.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 21: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/21.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 22: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/22.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
In a uniform magnetic field, H, a given nucleus can assumeany one of 2I + 1 orientations relative to the applied field
Each orientation corresponds to an energy
E = −γhH M2π
M = I , I − 1, I − 2,−IA proton coupled to a 11B nucleus “sees” four different fields,all equally probable
The 1H NMR spectrum of a proton coupled to a 11B nucleusis a quartet with all four peaks of equal intensity
5.03 Inorganic Chemistry
![Page 23: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/23.jpg)
Borohydride Ion [BH4]− has Td Symmetry
-2.5-2.0-1.5-1.0-0.50.00.51.01.52.02.53.03.54.01H NMR (ppm)
-0.8
1-0
.71
-0.6
4-0
.61
-0.5
7-0
.50
-0.4
4-0
.41
-0.3
7-0
.30
-0.2
0
1.93
1.94
1.95
1.95
CD3CN
NaBH4
5.03 Inorganic Chemistry
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Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
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Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
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Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
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Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
![Page 28: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/28.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
![Page 29: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/29.jpg)
Boron-11 NMRhttp://dx.doi.org/10.1021/ed054p469
5.03 Inorganic Chemistry
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Elemental Boron
Borax was known in antiquity and used to prepare glazes andhard borosilicate glasses
Impure boron was obtained by H. Davy, 1808, and byJ. L. Gay Lussac
H. Moissan obtained pure boron in 1892 by reduction of B2O3
using Mg
High purity boron and crystalline phases only obtained in thelater 20th century
The name “Boron” was proposed by Davy to indicate thesource of the element and its similarity to carbon, i.e. bor(ax+ carb)on
5.03 Inorganic Chemistry
![Page 32: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/32.jpg)
Elemental Boron
Borax was known in antiquity and used to prepare glazes andhard borosilicate glasses
Impure boron was obtained by H. Davy, 1808, and byJ. L. Gay Lussac
H. Moissan obtained pure boron in 1892 by reduction of B2O3
using Mg
High purity boron and crystalline phases only obtained in thelater 20th century
The name “Boron” was proposed by Davy to indicate thesource of the element and its similarity to carbon, i.e. bor(ax+ carb)on
5.03 Inorganic Chemistry
![Page 33: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/33.jpg)
Elemental Boron
Borax was known in antiquity and used to prepare glazes andhard borosilicate glasses
Impure boron was obtained by H. Davy, 1808, and byJ. L. Gay Lussac
H. Moissan obtained pure boron in 1892 by reduction of B2O3
using Mg
High purity boron and crystalline phases only obtained in thelater 20th century
The name “Boron” was proposed by Davy to indicate thesource of the element and its similarity to carbon, i.e. bor(ax+ carb)on
5.03 Inorganic Chemistry
![Page 34: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/34.jpg)
Elemental Boron
Borax was known in antiquity and used to prepare glazes andhard borosilicate glasses
Impure boron was obtained by H. Davy, 1808, and byJ. L. Gay Lussac
H. Moissan obtained pure boron in 1892 by reduction of B2O3
using Mg
High purity boron and crystalline phases only obtained in thelater 20th century
The name “Boron” was proposed by Davy to indicate thesource of the element and its similarity to carbon, i.e. bor(ax+ carb)on
5.03 Inorganic Chemistry
![Page 35: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/35.jpg)
Elemental Boron
Borax was known in antiquity and used to prepare glazes andhard borosilicate glasses
Impure boron was obtained by H. Davy, 1808, and byJ. L. Gay Lussac
H. Moissan obtained pure boron in 1892 by reduction of B2O3
using Mg
High purity boron and crystalline phases only obtained in thelater 20th century
The name “Boron” was proposed by Davy to indicate thesource of the element and its similarity to carbon, i.e. bor(ax+ carb)on
5.03 Inorganic Chemistry
![Page 36: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/36.jpg)
Elemental Boron comes from Borax
Borax, the mineral, contains the tetraborate ion,[B4O5(OH)4]2−
Borax is formulated as Na2[B4O5(OH)4]·8H2O
5.03 Inorganic Chemistry
![Page 37: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/37.jpg)
Elemental Boron comes from Borax
Borax, the mineral, contains the tetraborate ion,[B4O5(OH)4]2−
Borax is formulated as Na2[B4O5(OH)4]·8H2O
5.03 Inorganic Chemistry
![Page 38: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/38.jpg)
Elemental Boron comes from Borax
Borax, the mineral, contains the tetraborate ion,[B4O5(OH)4]2−
Borax is formulated as Na2[B4O5(OH)4]·8H2O
5.03 Inorganic Chemistry
![Page 39: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/39.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 40: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/40.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 41: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/41.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 42: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/42.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 43: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/43.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 44: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/44.jpg)
Elemental Boron
Boron is comparatively unabundant in the universe
It occurs to the extent of about 9 ppm in crustal rocks, sorather less abundant than lithium (18 ppm), but similar topraseodymium and thorium
Occurrance is invariably as borate minerals or borosilicates
Commercially valuable deposits are rare, but can be vast as inCalifornia and Turkey
Structural complexity of borate minerals is surpassed only bysilicates
Metal borides and allotropic modifications of boron also showgreat complexity and variety
5.03 Inorganic Chemistry
![Page 45: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/45.jpg)
Crystalline Boron
Structural complexity of boron arises from the way it seeks tosolve the problem of having fewer electrons than atomicorbitals available for bonding
Elements in this situation usually adopt metallic bonding
Due to its small size and high ionization energy, B engages incovalent bonding
The dominant structural unit is the B12 icosahedron, whichalso occurs in metal boride structures
Fivefold rotation symmetry at individual boron atoms givesrise to inefficient packing of B12 icosahedra, giving regularlyspaced voids to be occupied by metal or other atoms
5.03 Inorganic Chemistry
![Page 46: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/46.jpg)
Crystalline Boron
Structural complexity of boron arises from the way it seeks tosolve the problem of having fewer electrons than atomicorbitals available for bonding
Elements in this situation usually adopt metallic bonding
Due to its small size and high ionization energy, B engages incovalent bonding
The dominant structural unit is the B12 icosahedron, whichalso occurs in metal boride structures
Fivefold rotation symmetry at individual boron atoms givesrise to inefficient packing of B12 icosahedra, giving regularlyspaced voids to be occupied by metal or other atoms
5.03 Inorganic Chemistry
![Page 47: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/47.jpg)
Crystalline Boron
Structural complexity of boron arises from the way it seeks tosolve the problem of having fewer electrons than atomicorbitals available for bonding
Elements in this situation usually adopt metallic bonding
Due to its small size and high ionization energy, B engages incovalent bonding
The dominant structural unit is the B12 icosahedron, whichalso occurs in metal boride structures
Fivefold rotation symmetry at individual boron atoms givesrise to inefficient packing of B12 icosahedra, giving regularlyspaced voids to be occupied by metal or other atoms
5.03 Inorganic Chemistry
![Page 48: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/48.jpg)
Crystalline Boron
Structural complexity of boron arises from the way it seeks tosolve the problem of having fewer electrons than atomicorbitals available for bonding
Elements in this situation usually adopt metallic bonding
Due to its small size and high ionization energy, B engages incovalent bonding
The dominant structural unit is the B12 icosahedron, whichalso occurs in metal boride structures
Fivefold rotation symmetry at individual boron atoms givesrise to inefficient packing of B12 icosahedra, giving regularlyspaced voids to be occupied by metal or other atoms
5.03 Inorganic Chemistry
![Page 49: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/49.jpg)
Crystalline Boron
Structural complexity of boron arises from the way it seeks tosolve the problem of having fewer electrons than atomicorbitals available for bonding
Elements in this situation usually adopt metallic bonding
Due to its small size and high ionization energy, B engages incovalent bonding
The dominant structural unit is the B12 icosahedron, whichalso occurs in metal boride structures
Fivefold rotation symmetry at individual boron atoms givesrise to inefficient packing of B12 icosahedra, giving regularlyspaced voids to be occupied by metal or other atoms
5.03 Inorganic Chemistry
![Page 50: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/50.jpg)
Rhombohedral Boron
5.03 Inorganic Chemistry
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Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 55: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/55.jpg)
Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 56: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/56.jpg)
Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 57: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/57.jpg)
Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 58: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/58.jpg)
Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 59: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/59.jpg)
Boron CarbideJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Boron carbide has a unique combination of properties thatmake it a material of choice for a wide range of engineeringapplications
Boron carbide is used in refractory applications due to its highmelting point and thermal stability
It is used as abrasive powders and coatings due to its extremeabrasion resistance
It excels in ballistic performance due to its high hardness andlow density
It is commonly used in nuclear applications as a neutronradiation absorbent
Boron carbide is also a high temperature semiconductor
5.03 Inorganic Chemistry
![Page 60: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/60.jpg)
Boron Carbide StructureJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Elements are the B12 icosahedra and the C3 chains
Exact site occupancies are still debated due to similar electronand nuclear scattering cross-section for 11B and 12C isotopes
Idealized structural configuration is (B12)CCC, the carbon-richB4C compound
5.03 Inorganic Chemistry
![Page 61: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/61.jpg)
Boron Carbide StructureJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Elements are the B12 icosahedra and the C3 chains
Exact site occupancies are still debated due to similar electronand nuclear scattering cross-section for 11B and 12C isotopes
Idealized structural configuration is (B12)CCC, the carbon-richB4C compound
5.03 Inorganic Chemistry
![Page 62: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/62.jpg)
Boron Carbide StructureJ. Am. Ceram. Soc., 94 [11] 3605–3628 (2011) DOI: 10.1111/j.1551-2916.2011.04865.x
Elements are the B12 icosahedra and the C3 chains
Exact site occupancies are still debated due to similar electronand nuclear scattering cross-section for 11B and 12C isotopes
Idealized structural configuration is (B12)CCC, the carbon-richB4C compound
5.03 Inorganic Chemistry
![Page 63: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/63.jpg)
Boron Carbide Lattice Structure
5.03 Inorganic Chemistry
![Page 64: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/64.jpg)
![Page 65: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/65.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 66: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/66.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 67: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/67.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 68: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/68.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 69: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/69.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 70: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/70.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Success in a profession can often be traced to being in theright place at the right time
Became leader of exploratory research group at the Army’sRedstone Arsenal, 1950s
Mission was exploration of borane chemistry to be applied toCold War rocket motors
Ph.D. work was in physical organic chemistry; BF3 was theonly boron reagent he had used!
Decaborane, B10H14, was available from a jet engine fuelprogram, so investigated its characteristics in well-knownorganic reactions
Exploratory work revealed the borane analogs of aromatichydrocarbons, BnH2−
n with closed polyhedral structures
5.03 Inorganic Chemistry
![Page 71: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/71.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Another feature of boron is its two isotopes, 10B and 11B thatdiffer by an extra neutron in the 11B nucleus
Cancer therapy may benefit from the chemistry of boroncoupled to the reaction of the 10B nucleus with a neutron10B + 1n → 7Li + 4He + γ + 2.4 MeV
If the boron neutron capture reaction can be targeted tocancer cells, the Li and He products will kill the cell withoutdamage to the healthy neighboring cells
This highly specific reaction is unique among the lightelements
5.03 Inorganic Chemistry
![Page 72: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/72.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Another feature of boron is its two isotopes, 10B and 11B thatdiffer by an extra neutron in the 11B nucleus
Cancer therapy may benefit from the chemistry of boroncoupled to the reaction of the 10B nucleus with a neutron10B + 1n → 7Li + 4He + γ + 2.4 MeV
If the boron neutron capture reaction can be targeted tocancer cells, the Li and He products will kill the cell withoutdamage to the healthy neighboring cells
This highly specific reaction is unique among the lightelements
5.03 Inorganic Chemistry
![Page 73: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/73.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Another feature of boron is its two isotopes, 10B and 11B thatdiffer by an extra neutron in the 11B nucleus
Cancer therapy may benefit from the chemistry of boroncoupled to the reaction of the 10B nucleus with a neutron10B + 1n → 7Li + 4He + γ + 2.4 MeV
If the boron neutron capture reaction can be targeted tocancer cells, the Li and He products will kill the cell withoutdamage to the healthy neighboring cells
This highly specific reaction is unique among the lightelements
5.03 Inorganic Chemistry
![Page 74: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/74.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Another feature of boron is its two isotopes, 10B and 11B thatdiffer by an extra neutron in the 11B nucleus
Cancer therapy may benefit from the chemistry of boroncoupled to the reaction of the 10B nucleus with a neutron10B + 1n → 7Li + 4He + γ + 2.4 MeV
If the boron neutron capture reaction can be targeted tocancer cells, the Li and He products will kill the cell withoutdamage to the healthy neighboring cells
This highly specific reaction is unique among the lightelements
5.03 Inorganic Chemistry
![Page 75: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/75.jpg)
“Boron, my Favorite Element” Fred HawthorneVol. 86 No. 10 October 2009Journal of Chemical Education, 1131–1131
Another feature of boron is its two isotopes, 10B and 11B thatdiffer by an extra neutron in the 11B nucleus
Cancer therapy may benefit from the chemistry of boroncoupled to the reaction of the 10B nucleus with a neutron10B + 1n → 7Li + 4He + γ + 2.4 MeV
If the boron neutron capture reaction can be targeted tocancer cells, the Li and He products will kill the cell withoutdamage to the healthy neighboring cells
This highly specific reaction is unique among the lightelements
5.03 Inorganic Chemistry
![Page 76: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/76.jpg)
![Page 77: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/77.jpg)
“Boron, my Favorite Element” Fred Hawthorne
5.03 Inorganic Chemistry
![Page 78: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/78.jpg)
The Strongest Brønsted Acid
What is the strongest acid?
Can a simple Brønsted acid be prepared that can protonate analkane at room temperature?
Can that acid be free of the complicating effects of addedLewis acids that are typical of common superacid mixtures?
The carborane superacid H(CHB11F11) is that acid
5.03 Inorganic Chemistry
![Page 79: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/79.jpg)
The Strongest Brønsted Acid
What is the strongest acid?
Can a simple Brønsted acid be prepared that can protonate analkane at room temperature?
Can that acid be free of the complicating effects of addedLewis acids that are typical of common superacid mixtures?
The carborane superacid H(CHB11F11) is that acid
5.03 Inorganic Chemistry
![Page 80: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/80.jpg)
The Strongest Brønsted Acid
What is the strongest acid?
Can a simple Brønsted acid be prepared that can protonate analkane at room temperature?
Can that acid be free of the complicating effects of addedLewis acids that are typical of common superacid mixtures?
The carborane superacid H(CHB11F11) is that acid
5.03 Inorganic Chemistry
![Page 81: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/81.jpg)
The Strongest Brønsted Acid
What is the strongest acid?
Can a simple Brønsted acid be prepared that can protonate analkane at room temperature?
Can that acid be free of the complicating effects of addedLewis acids that are typical of common superacid mixtures?
The carborane superacid H(CHB11F11) is that acid
5.03 Inorganic Chemistry
![Page 82: Character Tables - MIT](https://reader031.vdocuments.mx/reader031/viewer/2022012502/617b635b80633071382366d4/html5/thumbnails/82.jpg)
The Strongest Brønsted Acid
What is the strongest acid?
Can a simple Brønsted acid be prepared that can protonate analkane at room temperature?
Can that acid be free of the complicating effects of addedLewis acids that are typical of common superacid mixtures?
The carborane superacid H(CHB11F11) is that acid
5.03 Inorganic Chemistry