Molecular hydrogen complexes. 6. The barrier to rotation of .eta.2-H2 in M(CO)3(PR3)2(.eta.2-H2) (M = tungsten, molybdenum; R = cyclohexyl, isopropyl): inelastic neutron scattering, theoretical, and molecular mechanics studies

The Activation of Dihydrogen

“…For example, the (g 2 -H 2 )W(CO) 3 (PCy 3 ) 2 complex, in which the d orbitals responsible for M ? H 2 back-donation are all filled and have reasonably similar energies, generally have low barriers to g 2 -H 2 rotation (DG = = 2.2 kcal mol -1 ) [41].…”

IMOMM: A new integrated ab initio + molecular mechanics geometry optimization scheme of equilibrium structures and transition states

“…A total energy E' can be readily defined from E L M : (12) Things are a little more complicated for the gadient, but only from a formal point of view. For R,, there is az, (13) where the last term of eq.…”

Structure and coordinate bonding nature of the manganese–σ–borane complexes

“…Theoretical calculations have also been carried out to substantiate the presence of g 2 -dihydrogen [9,[31][32][33][34][35][36][37] and g 2 -silane [15,[18][19][20][38][39][40][41] coordination to many different transition metal centers, but less attention has been paid to r-borane complexes. Ab initio calculations have been performed for r-borane complexes [(g 5 -C 5 H 5 )Ti{H-B(OH) 2 } 2 ] and [(g 5 -C 5 H 5 )Ti{HB(H) 2 r-borate complexes [(g 5 -C 5 H 5 ) 2 Nb{H 2 B(OH) 2 }] [42], [(g 5 -C 5 H 5 )Nb{H 2 B(C 8 H 14 )] and [(g 5 -C 5 H 5 )Nb{H 2 B(H) 2 }] [43].…”