M. Cinellu, M. Ganadu, G. Minghetti
Mar 15, 1988
Citations
1
Influential Citations
20
Citations
Journal
Inorganica Chimica Acta
Abstract
Abstract The adducts trans-L2PdCl2 (1, L = Diazepam = 7- chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin -2-one; 5, L = Prazepam = 7-chloro-1-(cyclopropylmethyl)- 1,3-dihydro-5-phenyl-2H-1,4-benzodiazepin-2-one) were prepared by reaction of PdCl2 or (PhCN)2PdCl2 with Diazepam and Prazepam, respectively. In the adducts, the benzodiazepines act as monodentate ligands through the 4-nitrogen atom, as shown by the structure of compound 5, determined by X-ray diffraction. Two crystalline modifications have been characterized: 5a, trans-(Prazepam)2PdCl2/CHCl3 1/1, monoclinic, space group P21/n, a = 11.996(4), b = 13.678(5), c = 12.717(3) A, β = 98.83(2), Z = 2, R = 0.032; 5b, trans-(Prazepam)2PdCl2/CH2Cl2 1/1, monoclinic, space group P21/c, a = 14.074(3), b = 14.622(7), c = 19.360(10) A, β = 100.04(3), Z = 4, R = 0.076. Cyclometallated derivatives [(LH)PdCl]2, 2, L = Diazepam and 6, L = Prazepam, involving both C- and N-intramolecular coordination of the deprotonated ligands, have been obtained by reaction with Na2[PdCl4] in ethanol solution. In the dimeric species 2 and 6, the halide-bridge is easily split by reaction with Ph3P or Tl(acac), to give [(LH)·(Ph3P)PdCl], (3, 7) and [(LH)Pd(acac)] (4, 8) respectively.