Synthesis of RuHCl(CO)(Hdmpz)(L)2 (L=PPh3, AsPh3, and Hdmpz=3,5-dimethylpyrazole) and crystal structure of RuHCl(CO)(Hdmpz)(AsPh3)2

Facile Pyrazolylborate Ligand Degradation at Lanthanide Centers: X-ray Crystal Structures of Pyrazolylborinate-Bridged Bimetallics

“…For example, Jun et al found that, at a Ru center in methanol, Tp Me2 and Bp Me2 ligands are completely degraded whereas isolable complexes are obtained using Bp and Bp 4-Br . 48 For the lanthanides, several Tp, [73][74][75][76][77][78][79][80][81][82][83][84][85] HB(btz) 3 (btz ) benzotriazolyl), 86 and Tp py 87 complexes have been prepared in aqueous or alcoholic solutions. Onishi and co-workers, however, have reported fragmented products from preparations of TpLnX 2 -type complexes.…”

“…For example, Jun et al. found that, at a Ru center in methanol, Tp Me2 and Bp Me2 ligands are completely degraded whereas isolable complexes are obtained using Bp and Bp 4-Br . For the lanthanides, several Tp, − HB(btz) 3 (btz = benzotriazolyl), and Tp py 87 complexes have been prepared in aqueous or alcoholic solutions.…”

“…Such reactions have been described both for maingroup metal complexes [35][36][37][38] and for transition metals. [39][40][41][42][43][44][45][46][47][48][49][50] This propensity to decomposition has become particularly manifest for the Tp Me2 ligand bound to lanthanide centers. Attempts to prepare half-sandwich complexes of the type [Ln(Tp Me2 )X 2 ] have resulted in the isolation of dimethylpyrazole adducts [Ln(Tp Me2 )X 2 (dmpzH)], dimethyl pyrazole being the logical product of Tp Me2 hydrolysis.…”

“…Ligand rearrangements, believed to involve either 1,2-borotropic or 1,2-metallatropic shifts, have been observed for a number of ligands of intermediate steric demand. − More problematic has been the observation of partial and even complete degradation of such ligands within the coordination sphere of metals. Such reactions have been described both for main-group metal complexes − and for transition metals. − This propensity to decomposition has become particularly manifest for the Tp Me2 ligand bound to lanthanide centers. Attempts to prepare half-sandwich complexes of the type [Ln(Tp Me2 )X 2 ] have resulted in the isolation of dimethylpyrazole adducts [Ln(Tp Me2 )X 2 (dmpzH)], dimethyl pyrazole being the logical product of Tp Me2 hydrolysis.…”