METAL-COMPLEXES OF BENZODIAZEPINES .3. SYNTHESIS AND CHARACTERIZATION OF ORGANOMETALLIC COMPLEXES OF PLATINUM(II)

The complexes cis-[PtMe2(Me2SO)L1] and [PtR2L2] (R = Me or Ph) are easily obtained by reaction in CH2Cl2 of the complexes [PtMe2(Me2SO)2] or [{PtPh2(Et2S)}2] with L1 = 2,3-dihydro-2,2,4-trimethyl-1H-1,5-benzodiazepine or L2 = bromazepam = 7-bromo-1,3-dihydro-5-(2-pyridyl)2-H-1,4-benzodiazepin-2-one. They are the first examples of simple organometallic adducts of benzodiazepines with platinum(II). Their H-1 and C-13 NMR spectra suggest the co-ordination of L1 through N5, while L2 acts as a bidentate ligand by means of the imine and pyridine nitrogen atoms. The co-ordinated heterocyclic rings show a notable increase in their inversion barrier.