Triply-bridged diruthenium(II) 1,4-bis(diphenylphosphino)butane (dppb) and ( R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) complexes, including structural characterisation of [(dppb) ClRu( μ-D 2O)-( μ-Cl) 2RuCl(dppb)], [( η2-H 2) (dppb)Ru( μ-Cl) 3RuCl(dppb)] and the [(dppb)ClRu( μ-Cl) 3RuCl(dppb)] − anion

Abstract

Several triply-bridged diruthenium(II)(1,4-bis(diphenylphosphino)butane) complexes were synthesised and characterised by elemental analysis, UV-Vis, NMR and IR spectroscopies. The solid-state structures of [(dppb)ClRu( μ-D 2O)( μ-Cl) 2RuCl(dppb)] ( 1), [( η 2-H 2) (dppb)Ru( μ-Cl) 3RuCl(dppb)] ( 2) and [Tmp][(dppb)ClRu( μ-Cl) 3RuCl(dppb)] ( 3) were established by X-ray crystallographic analyses (TMP = 1,1,3-trimethyl-2,3-dihydroperimidinium; dppb = Ph 2P(CH 2) 4PPh 2). Crystals of 1·1.5C 6D 6, 2·1.5C 7D 8 and 3·2Me 2CO·2H 2O are all monoclinic, space groups P2 1/ c, P2 1/ n and C2/ c, respectively, with Z = 4; a = 16.8681(6), b = 13.3542(4), c = 26.4966(7) Å, β = 91.877(1)° for 1·1.5C 6D 6; a = 19.8123(1), b = 14.5246(2), c = 22.1803(1) Å, β = 106.58(1)° for 2·1.5C 7D 8; a = 21.596(2), b = 16.019(2), c = 22.317(2) Å, β= 106.15(1)° for 3·2Me 2CO·2H 2O. The structures of 1 and 2 were solved by direct methods while 3 was solved by heavy atom methods and all were refined by full-matrix least-squares procedures to R 1 = 0.0433, 0.0612 and R = 0.039 ( wR 2 = 0.0709 ( 1), 0.1178 ( 2)) for 7751, 6757 and 5237 reflections with I ≥ 2 σ( I) for 1 and 2 and I ≥ 3 σ( I) for 3, respectively. Complex 1 was also studied in the solid-state by 31P CP/MAS NMR spectroscopy. The bromo- and iodo-analogues of 1 were prepared, and these three species were screened as catalysts for hydrogenation of aldimines. The complexes [H 2NR 2][{RuCl(P-P)} 2( μ-Cl) 3] were synthesised by the addition of NR 3 or [H 2NR 2]Cl to RuCl 2(P-P) (PPh 3), where P-P = dppb or ( R)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) and R - Et, n-Bu or n-Oct. The syntheses of [(DMA) 2H][(PPh 3) 2ClRu( μ-Cl) 3RuCl(PPh 3) 2], [(py)(dppb)Ru( μ-Cl) 3RuCl(dppb)] and [(C 2H 4) (dppb)Ru( μ-Cl) 3RuCl(dppb)] were also accomplished (DMA = N,N-dimethylacetamide; py = pyridine).