Polypyrazolylmethane complexes of ruthenium

A series of ruthenium(II) complexes with the pyrazolyl alkane ligands tris( 1-pyrazolyl)methane 1 (TPM) and bis(1-pyrazolyl)methane 2 (BPM) have been s ynthesized and characterised. The complex [RuCl(PPh3)(2)(TPM)]X+ (X = Cl 3a or BF4 3b) was formed by the reaction of TPM with RuCl2(PPh3)(3) and [Ru(C O)H(PPh3)(TPM)]X+ (X = Cl 4a or BF4 4b) by the reaction of TPM with Ru(CO)C lH(PPh3)(3). The complexes [RuCl(PPh3)(BPM)(2)]Cl-+(-) 5 and (BPM)(Ph3P)Ru( mu -Cl)(3)Ru(PPh3)(BPM)]Cl-+(-) 6 were synthesized by the reaction of BPM w ith RuCl2(PPh3)(3). Complexes 3-6 were characterised by multinuclear NMR sp ectroscopy, and 3a and 6 by X-ray crystallography. [RuCl(PPh3)(2)(TPM)]Cl-(-) exhibits dynamic behaviour at low temperature and this is attributed to restricted rotation of the PPh3 groups about the M-P bond.