A novel ruthenium nitrosyl complex which also contains a free NO-donor moiety

The synthesis and characterisation of a novel ruthenium nitrosyl complex with coordinated 4-pyridinehydroxamic acid, [NBu4][cis-RuCl4(4-pyha)NO] (4-pyha=4-pyridinehydroxamic acid, NO=nitric oxide) is reported. [NBu4][cis-RuCl4(4-pyha)NO] was prepared from the precursor, NBu4[trans-RuCl4(dmso-O)NO] (dmso=dimethylsulfoxide) upon treatment with 4-pyridinehydroxamic acid. [NBu4][cis-RuCl4(4-pyha)NO] possesses the linear {RuII(NO)+} moiety and a cis-pyridinehydroxamic acid group which has the potential to act as an NO donor. The crystal structure of [NBu4][cis-RuCl4(4-pyha)NO] was also determined. The nitrosyl complex is novel in that, besides coordinated NO, it also contains a ligand which has the potential to release NO.