TY - JOUR
T1 - Theoretical studies of inorganic compounds. 36 Structures and bonding analyses of beryllium chloro complexes with nitrogen donors
AU - Metz, Sebastian
AU - Holthausen, Max C.
AU - Frenking, Gernot
PY - 2006
Y1 - 2006
N2 - Quantum chemical calculations at various levels of theory (BP86, B3LYP, MP2, CCSD(T), CBS-QB3) of the beryllium complexes [BeCl2(NHPH 3)], [BeCl2(NHPH3)2], [BeCl 3(py)]-, [BeCl2(NH3)], [BeCl 2(NH3)2], [BeCl3(py)]- and [BeCl3(NH3)]- as well as the boron compounds [BCl3(py)] and [BCl3(NH3)] show that BeCl2 is a very strong Lewis acid. The theoretically predicted bond dissociation energy at CBS-QB3 of Cl2Be-NH3 (De = 32.5 kcal/mol) is even higher than that of Cl3B-NH3 (De = 28.6kcal/mol). Even the second ammonia molecule in [BeCl 2(NH3)2] still has a strong bond with D e = 24.2 kcal/mol. The theoretically predicted bond strengths for the phosphaneimine ligands in [BeCl2(NHPH3)2] are De = 46.7 kcal/mol for the first ligand and De = 29.8 kcal/mol for the second. The anion BeCl3 - is a moderately strong Lewis acid which has bond energies of De = 14.1 kcal/mol in [BeCl3(py)]- and De = 14.2 kcal/mol in [BeCl3(NH3)]-. The higher bond energy of [BeCl2(NH3)] compared with [BCl3(NH 3)] comes from less deformation energy for BeCl2 than for BCl3. The intrinsic attraction between BeCl2 and NH 3 calculated with frozen geometries of the complex geometry is ∼5 kcal/mol less than the attraction between BCl3 and NH3. The bonding analysis with the EDA method shows that the attractive energy of the beryllium complexes comes manly from electrostatic attraction. The larger contribution of the electrostatic term is the most significant difference between the nature of the donor-acceptor bonds of the beryllium and boron complexes.
AB - Quantum chemical calculations at various levels of theory (BP86, B3LYP, MP2, CCSD(T), CBS-QB3) of the beryllium complexes [BeCl2(NHPH 3)], [BeCl2(NHPH3)2], [BeCl 3(py)]-, [BeCl2(NH3)], [BeCl 2(NH3)2], [BeCl3(py)]- and [BeCl3(NH3)]- as well as the boron compounds [BCl3(py)] and [BCl3(NH3)] show that BeCl2 is a very strong Lewis acid. The theoretically predicted bond dissociation energy at CBS-QB3 of Cl2Be-NH3 (De = 32.5 kcal/mol) is even higher than that of Cl3B-NH3 (De = 28.6kcal/mol). Even the second ammonia molecule in [BeCl 2(NH3)2] still has a strong bond with D e = 24.2 kcal/mol. The theoretically predicted bond strengths for the phosphaneimine ligands in [BeCl2(NHPH3)2] are De = 46.7 kcal/mol for the first ligand and De = 29.8 kcal/mol for the second. The anion BeCl3 - is a moderately strong Lewis acid which has bond energies of De = 14.1 kcal/mol in [BeCl3(py)]- and De = 14.2 kcal/mol in [BeCl3(NH3)]-. The higher bond energy of [BeCl2(NH3)] compared with [BCl3(NH 3)] comes from less deformation energy for BeCl2 than for BCl3. The intrinsic attraction between BeCl2 and NH 3 calculated with frozen geometries of the complex geometry is ∼5 kcal/mol less than the attraction between BCl3 and NH3. The bonding analysis with the EDA method shows that the attractive energy of the beryllium complexes comes manly from electrostatic attraction. The larger contribution of the electrostatic term is the most significant difference between the nature of the donor-acceptor bonds of the beryllium and boron complexes.
KW - Beryllium
KW - Bonding analysis
KW - Quantum chemical calculations
UR - http://www.scopus.com/inward/record.url?scp=33646196957&partnerID=8YFLogxK
U2 - 10.1002/zaac.200500438
DO - 10.1002/zaac.200500438
M3 - 文章
AN - SCOPUS:33646196957
SN - 0044-2313
VL - 632
SP - 814
EP - 818
JO - Zeitschrift fur Anorganische und Allgemeine Chemie
JF - Zeitschrift fur Anorganische und Allgemeine Chemie
IS - 5
ER -