| LÖBL, Jiří, Alexey Y. TIMOSHKIN, Cong TRINH, Marek NEČAS, Herbert W. ROESKY a Jiří PINKAS. Alumazene Adducts with Pyridines: Synthesis, Structure, and Stability Studies. INORGANIC CHEMISTRY. Spojené státy americké: American Chemical Society, Washington DC, 2007, roč. 46, č. 14, s. 5678-5685. ISSN 0020-1669. |
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@article{721246,
author = {Löbl, Jiří and Timoshkin, Alexey Y. and Trinh, Cong and Nečas, Marek and Roesky, Herbert W. and Pinkas, Jiří},
article_location = {Spojené státy americké},
article_number = {14},
keywords = {Lewis acid-base; adducts; alumazene; pyridine},
language = {eng},
issn = {0020-1669},
journal = {INORGANIC CHEMISTRY},
title = {Alumazene Adducts with Pyridines: Synthesis, Structure, and Stability Studies},
volume = {46},
year = {2007}
}
TY - JOUR
ID - 721246
AU - Löbl, Jiří - Timoshkin, Alexey Y. - Trinh, Cong - Nečas, Marek - Roesky, Herbert W. - Pinkas, Jiří
PY - 2007
TI - Alumazene Adducts with Pyridines: Synthesis, Structure, and Stability Studies
JF - INORGANIC CHEMISTRY
VL - 46
IS - 14
SP - 5678-5685
EP - 5678-5685
PB - American Chemical Society, Washington DC
SN - 00201669
KW - Lewis acid-base
KW - adducts
KW - alumazene
KW - pyridine
N2 - Lewis acid-base adducts of the alumazene [2,6-(i-Pr)2C6H3NAlMe]3 (1) with pyridine (py) and 4-dimethylaminopyridine (dmap) were synthesized and structurally characterized: 1(py)2 (2), 1(py)3 (3), 1(dmap)2, (4), and 1(py)(dmap) (5). The bisadducts 2, 4, and 5 form the trans isomers. The trisadduct 3 exhibits an unexpected cis-cis isomer and can be prepared only in the presence of excess py. The planarity of the alumazene ring is lost upon coordination of the Lewis base molecules. A comparison of the Al-N(base) bond distances and pyramidality at Al suggests the higher basicity of dmap. NMR spectroscopy confirms stability to dissociation of the bisadducts in solution while the trisadduct 3 is labile and converts to 2. The thermodynamics of the adduct formation has been investigated experimentally and theoretically. Thermodynamic characteristics of the 1(py)n (n = 2, 3) dissociation reactions in the temperature range 25-200 oC have been derived from the vapor pressure-temperature dependence measurements by the static tensimetric method. In all experiments excess py was employed. Quantum chemical computations at the B3LYP/6-31G* level of theory have been performed for the 1(py)n and model complexes [HAlNH]3(py)n (n = 1-3). Obtained results indicate that for the gas phase adducts upon increasing the number of py ligands the donor-acceptor Al-N(py) distance increases in accord with decreasing donor-acceptor bond dissociation energies.
ER -
LÖBL, Jiří, Alexey Y. TIMOSHKIN, Cong TRINH, Marek NEČAS, Herbert W. ROESKY a Jiří PINKAS. Alumazene Adducts with Pyridines: Synthesis, Structure, and Stability Studies. \textit{INORGANIC CHEMISTRY}. Spojené státy americké: American Chemical Society, Washington DC, 2007, roč.~46, č.~14, s.~5678-5685. ISSN~0020-1669.
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