Molybdenum complexes with noninert-gas configuration

Notizen: The Bishydridobis(tetrazol-1-yl)borate Anion, [H2B(CHN4)2]-: Synthesis and Structure of the First Tetrazolylborate

“…In consonance with earlier reports on the syntheses of poly(azolyl)borates [8], potassium boranate (K B H 4) was found to react with tetrazole (C H ,N 4). When a mixture of KBH4 and tetrazole is heated to about 100 C two moles of H 2 are evolved and a white solid is obtained whose ele mental analysis is consistent with the potassium bishydridobis(tetrazolyl)borate formula (1 ).…”

Agostic interactions in transition metal compounds

“…An exemplary illustration of such a complex that features an M⅐⅐⅐H-N hydrogen bond is provided by [Et 3 NH][Co(CO) 4 ] (31). In this complex, the [Co(CO) 4 ] Ϫ anion has an 18-electron configuration and is devoid of a vacant orbital in the valence shell; as such, the metal is incapable of participating in a 3-center-2-electron M-H-N interaction. Because C-H groups are known to be weak hydrogen bond donors, Brammer et al (29) raised the possibility that some M-H-C interactions could be better described as ''hydrogen bonds'' rather than agostic interactions.…”

“…In addition to trans-Pd(PPh 3 ) 2 {C 4 (CO 2 Me) 4 H}Br, Brammer and coworkers noted that a variety of other compounds could also possibly be described as possessing M-H-C hydrogen bonds (for example, see been recognized that the M-H-C interactions were not the same as that in traditional agostic compounds, the distinction suggested by Brammer had not been emphasized. Indeed, Venanzi and coworkers (37) actually introduced the term ''pregostic'' to describe such complexes, with the interpretation being that the interaction is preagostic, i.e., on the way to becoming agostic.…”

Synthesis and characterization of LMo(CO)3M(PPh3)x (where L = tridentate pyrazolyl-gallate or -borate ligand; M = Rh, x = 2; M = Cu, x = 1). X-ray crystal structures of [MeGapz3]Mo(CO)3Rh(PPh3)2 and [MeGapz3]Mo(CO)3Cu(PPh3) (where pz = pyrazolyl, N2C3H3)

“…8. K+HBpz3-of unsymmetrical, uninegative, tridentate ligands having both (9), (MeCN),Mo(CO), (lo), and [Cu(PPh3)C1I4 (1 1 likened to, and compared with, the cyclopentadienyl ion in he Na+L-ligand solution (-0. 4 -01 in 100 mL) was added to a many "isoelectronic" complexes (4-7).…”