Carbonyl and nitrosyl diruthenium compounds:: Crystal structure of [Ru2(O2CMe)(DPhF)3(CO)]BF4 • CH2Cl2 and its isomorphous nitrosyl analogue

The reaction of [Ru-2(O2CMe)(DPhF)(3)(H2O)]BF4 (DPhF = N,N'-diphenylformamidinate) with CO gas leads to [Ru-2(O2CMe)-(DPhF)(3)(CO)]BF4 (1), that is the first isolated carbonyl complex containing the Ru-2(5+) unit. The nitrosyl analogue [Ru-2(O2CMe)-(DPhF)(3)(NO)]BF4 (2) is prepared by reaction of Ru2Cl(O2CMe)(DPhF)(3) with NOBF4. However, the attempts to obtain the cyanide derivative by reaction of Ru2Cl(O2CMe)(DPhF)(3) or [Ru-2(O2CMe)(DPhF)(3)(H2O)]BF4 with NaCN were unsuccessful. The structure of compounds 1 center dot CH2Cl2 and 2 center dot CH2Cl2 are described. Both compounds are isomorphous. The magnetic measurements at variable temperature demonstrate that 1 is paramagnetic with one unpaired electron in all range of temperature, in contrast to the three unpaired electrons usually present in Ru-2(5+) complexes. The analogous nitrosyl compound 2 is diamagnetic. (C) 2007 Elsevier B.V. All rights reserved.