Nature of the bond, reduction potential, and solvation properties of ruthenium nitrosyl complexes of the type trans-</i> [Ru( <scp> NH 3</sub> </scp> ) 4</sub> (L)( <scp>NO</scp> )] 2+/3+</sup> and [Ru(salen)(L)( <scp>NO</scp> )] 2+/3+</sup> in different charge and spin states