Bond Formation and Coupling between Germyl and Bridging Germylene Ligands in Dinuclear Palladium(I) Complexes

Abstract

The dinuclear palladium(I) complexes [L(Ar2 HGe)Pd(μ-GeAr2 )2 Pd(GeHAr2 )L] (Ar=Ph, p-Tol; L=PMe3 , tBuNC) contain terminal germyl and bridging germylene ligands with the experimentally observed Ge⋅⋅⋅Ge bond lengths of 2.8263(4) Å (L=PMe3 ) and 2.928(1) Å (L=tBuNC), which are close to the longest Ge-Ge bond reported to date [2.714(1) Å]. Significant Ge⋅⋅⋅Ge interactions between the germylene and germyl ligands (PMe3 complexes > tBuNC complexes) are supported by DFT calculations, Wiberg bond indices (WBI), and natural bond orbital (NBO) analyses. Exchanging tBuNC for PMe3 ligands increases the Ge⋅⋅⋅Ge interaction, and simultaneously activates two Pd-Ge bonds. Adding the chelating diphosphine 1,2-bis(diethylphosphino)ethane (depe) to the PMe3 complexes results in the intramolecular coupling of germyl and germylene ligands followed by extrusion of a digermane.

Photochemical Oxidative Addition of Germane and Diphenylgermane to Ruthenium Dihydride Complexes

“…After leaving the sample overnight, 1 . Although the hydride resonance of this product overlaps with that of the germyl analogue in the 1 H spectrum, clean separation is achieved by 31 Ru(dppe)2H2 1Ph, was synthesized following the reported procedure. 53 Germane gas was prepared according to a procedure based on Woollins.…”

“…A remarkable reaction occurs between cis -PdMe 2 (PMe 3 ) 2 and diphenylgermane in the presence of t BuNC yielding a complex with a Pd 2 Ge 4 core with close Ge···Ge interactions. Further reaction with depe releases the digermane HPh 2 Ge–GePh 2 H and forms Pd–Ge complexes; heating this mixture gives a trigermane HPh 2 Ge–GePh 2 –GePh 2 H …”

“…H{31 P}-31 P HMQC spectroscopy. Upon broad-band31 P decoupling, both hydride and germyl resonances simplify to singlets, and give a ratio of 4.5:1, of cis-to trans-products.…”

“…H{31 P}-31 P HMQC spectroscopy. Upon broad-band31 P decoupling, both hydride and germyl resonances simplify to singlets, and give a ratio of 4.5:1, of cis-to trans-products. The 31 P{ 1 H} NMR spectrum also shows the formation of two new major products: the cisspecies contains magnetically inequivalent phosphorus atoms, leading to an ABQX spin system.…”

Cationic dinuclear platinum and palladium complexes with bridging hydrogermylene and hydrido ligands

“…Dinuclear platinum and palladium complexes bearing bridging ligands have attracted attention because of unusual circumstances arising from the strong electronic effect of two metal centers. 1 In particular, m-silylene [2][3][4] and m-germylene 5,6 dinuclear Group 10 metal complexes are of considerable interest for their unique structures and reactivity involving various coordination modes. As cationic analogues, although a few number of diplatinum complexes containing m-alkylidene and m-hydrido ligands, [{Pt(L-L)} 2 (m-CHR)(m-H)] + [L-L = chelate phosphine ligand], have been published, 7 the synthesis and isolation of their m-silylene or m-germylene congeners have been scarce to date, probably due to a lack of suitable synthetic methods.…”