The reactivity of new (1,5-cyclooctadiene)rhodium acylpyrazolonates towards N- and P-donor ligands: X-ray structures of [Rh(1,5-COD)QS], [Rh(1,5-COD)(phen)]QS.0.5H2O (HQS = 1-phenyl-3-methyl-4-(2-thienoyl)-pyrazol-5-one) and [Rh(1,5-COD)Br]2