Trimethylaluminum

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Gas phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: José A. Martinho Simões

Quantity Value Units Method Reference Comment
Δfgas-86.5 ± 4.8kJ/molReviewMartinho SimõesSelected data. The enthalpy of formation relies on -1891.3 ± 1.9 kJ/mol for the enthalpy of formation of Al(OOCMe)3(cr) and on 0.9 ± 0.2 kJ/mol for the enthalpy of solution of MeCOOH(l) in toluene Mortimer and Sellers, 1963. Liquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.
Δfgas-57.0 ± 9.7kJ/molReviewMartinho SimõesLiquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.
Δfgas-88.7kJ/molReviewMartinho SimõesThe enthalpy of formation was quoted from Smith, 1974 and relies on experimental data in Tröber and Stricker, 1966. Liquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.

Condensed phase thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
MS - José A. Martinho Simões
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Δfliquid-149.7 ± 4.5kJ/molReviewMartinho SimõesSelected data. The enthalpy of formation relies on -1891.3 ± 1.9 kJ/mol for the enthalpy of formation of Al(OOCMe)3(cr) and on 0.9 ± 0.2 kJ/mol for the enthalpy of solution of MeCOOH(l) in toluene Mortimer and Sellers, 1963. Liquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.; MS
Δfliquid-120.2 ± 9.6kJ/molReviewMartinho SimõesLiquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.; MS
Δfliquid-151.9kJ/molCC-SBSmith, 1974Value corrected based on a set of ancillary data by J.A. Martinho Simões; The enthalpy of formation was quoted from Smith, 1974 and relies on experimental data in Tröber and Stricker, 1966. Liquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.; MS
Quantity Value Units Method Reference Comment
Δcliquid-3184.4 ± 9.6kJ/molCC-SBLong and Norrish, 1949Please also see Cox and Pilcher, 1970. Liquid trimethylaluminum contains a very small molar fraction of monomer at 298 K, ca. 0.007% Smith, 1972, so that the "real" liquid should be described as [Al(Me)3]2.; MS
Quantity Value Units Method Reference Comment
liquid209.41J/mol*KN/AMcCullough, Messerly, et al., 1963DH

Constant pressure heat capacity of liquid

Cp,liquid (J/mol*K) Temperature (K) Reference Comment
155.60298.15McCullough, Messerly, et al., 1963T = 10 to 380 K.; DH

Reaction thermochemistry data

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
B - John E. Bartmess
MS - José A. Martinho Simões

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

Hydrogen anion + Trimethylaluminum = (Hydrogen anion • Trimethylaluminum)

By formula: H- + C3H9Al = (H- • C3H9Al)

Quantity Value Units Method Reference Comment
Δr>354.8 ± 2.1kJ/molIMRBden Berg, Ingemann, et al., 1992gas phase; Hydride affinity > (CF3)2CO. Computations indicate HOF(A-) ca. -46 kcal/mol, dHaff ca. 74 kcal/mol; B

C6H18Al2 (l) = 2Trimethylaluminum (l)

By formula: C6H18Al2 (l) = 2C3H9Al (l)

Quantity Value Units Method Reference Comment
Δr81.2 ± 1.3kJ/molEqSSmith, 1972MS

Vibrational and/or electronic energy levels

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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled by: Marilyn E. Jacox

State:   X


Vib. 
sym. 
 No.   Approximate 
 type of mode 
 cm-1   Med.   Method   References

a1' 1 CH3 s-stretch 2920 gas Ra O'Brien and Ozin, 1971
2 CH3 deform. 1200 gas Ra O'Brien and Ozin, 1971
3 AlC3 s-stretch 530 gas Ra O'Brien and Ozin, 1971
a2 7 CH3 a-stretch 2948 s Ar IR Kvisle and Rytter, 1984
9 CH3 rock 744 vs gas IR Atiya, Grady, et al., 1991
9 CH3 rock 742 s Ar IR Kvisle and Rytter, 1984
e' 11 CH3 a-stretch 2982 m gas IR Ra O'Brien and Ozin, 1971
Atiya, Grady, et al., 1991
11 CH3 a-stretch 2971 s Ar IR Kvisle and Rytter, 1984
12 CH3 s-stretch 2901 m gas IR Ra O'Brien and Ozin, 1971
Atiya, Grady, et al., 1991
12 CH3 s-stretch 2905 m Ar IR Kvisle and Rytter, 1984
13 CH3 a-deform. 1430 w T gas IR Ra O'Brien and Ozin, 1971
Atiya, Grady, et al., 1991
13 CH3 a-deform. 1430 w T Ar IR Kvisle and Rytter, 1984
14 CH3 s-deform. 1202 s gas IR Atiya, Grady, et al., 1991
14 CH3 s-deform. 1196 s Ar IR Kvisle and Rytter, 1984
15 CH3 rock 754 s T gas IR Ra O'Brien and Ozin, 1971
Atiya, Grady, et al., 1991
16 AlC3 a-stretch 691 m s gas IR Atiya, Grady, et al., 1991
16 AlC3 a-stretch 689 s Ar IR Kvisle and Rytter, 1984
17 AlC3 deform. 170 gas Ra O'Brien and Ozin, 1971
e 18 CH3 a-stretch 2951 gas Ra O'Brien and Ozin, 1971
19 CH3 a-deform. 1440 gas Ra O'Brien and Ozin, 1971
20 CH3 rock 717 w Ar IR Kvisle and Rytter, 1984

Additional references: Jacox, 1994, page 400

Notes

wWeak
mMedium
sStrong
vsVery strong
TTentative assignment or approximate value

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Vibrational and/or electronic energy levels, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Martinho Simões
Martinho Simões, J.A., Private communication (see http://webbook.nist.gov/chemistry/om/). [all data]

Mortimer and Sellers, 1963
Mortimer, C.T.; Sellers, P., J. Chem. Soc., 1963, 1978.. [all data]

Smith, 1972
Smith, M.B., J. Organometal. Chem., 1972, 46, 31. [all data]

Smith, 1974
Smith, M.B., J. Organometal. Chem., 1974, 76, 171. [all data]

Tröber and Stricker, 1966
Tröber, A.; Stricker, C., Wiss Z. Tech. Hochsch. Chem. "Carl Schlorlemmer" Leuna-Merseburg, 1966, 8, 34. [all data]

Long and Norrish, 1949
Long, L.H.; Norrish, R.G.W., Phil. Trans. Roy. Soc. (London), 1949, A241, 587. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds in Academic Press, New York, 1970. [all data]

McCullough, Messerly, et al., 1963
McCullough, J.P.; Messerly, J.F.; Moore, R.T.; Todd, S.S., Trimethylaluminum: thermodynamic functions in the solid and liquid states, 0-380°K, vapor pressure, heat of vaporization, and entropy in the ideal gas state, J. Phys. Chem., 1963, 67, 677-679. [all data]

den Berg, Ingemann, et al., 1992
den Berg, K.J. van; Ingemann, S.; Nibbering, N.M.M., Gas Phase Reactions of Negative Ions with Trimethylaluminum: Formation and Reactivity of the Me3AlH- Ion., Org. Mass Spectrom., 1992, 27, 4, 523, https://doi.org/10.1002/oms.1210270427 . [all data]

O'Brien and Ozin, 1971
O'Brien, R.J.; Ozin, G.A., J. Chem. Soc. A, 1971, 1136. [all data]

Kvisle and Rytter, 1984
Kvisle, S.; Rytter, E., Spectrochim. Acta 40A, 1984, 939. [all data]

Atiya, Grady, et al., 1991
Atiya, G.A.; Grady, A.S.; Russell, D.K.; Claxton, T.A., Spectrochim. Acta, 1991, 47A, 467. [all data]

Jacox, 1994
Jacox, M.E., Vibrational and electronic energy levels of polyatomic transient molecules, American Chemical Society, Washington, DC, 1994, 464. [all data]


Notes

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