Synthesis, crystal structures, and vibrational spectra of [Pt(N-3)(6)](2-)and [Pt(N-3)Cl-5](2-), Pt-195 and N-15 NMR spectra of [Pt(N-3)(n)Cl6-n](2-) and [Pt((NN2)-N-15)(n)((N2N)-N-15)(6-n)](2-), n=0-6

By ligand exchange of [PtCl6](2-) with sodium azide mixed complexes of the series [Pt(N-3)(n)Cl6-n](2-) and with N-15-labelled sodium azide ((NaNN2)-N -15) mixtures of the isotopomeres [Pt((NN2)-N-15)(n)((N2N)-N-15)(6-n)](2-), n = 0-6 and the pair [Pt((NN2)-N-15)Cl-5](2-)/[Pt((N2N)-N-15)Cl-5](2-) are formed. X-ray structure determinations on single crystals of (Ph4P)(2)[Pt( N-3)(6)] (1) (triclinic, space group P (1) over bar, a = 10.175(1), b = 10. 516(1), c = 12.380(2) Angstrom, alpha = 87.822(9), beta = 73.822(9), gamma = 67.987(8)degrees, Z = 1) and (Ph4As)(2)[Pt(N-3)Cl-5] . HCON(CH3)(2) (2) ( triclinic, space group P (1) over bar, a = 10.068(2), b = 11.001(2), c = 23 .658(5) Angstrom, alpha = 101.196(14), beta = 93.977(15), gamma = 101.484(1 3)degrees, Z = 2) have been performed. The bond lengths are Pt-N = 2.088 (1 ), 2.105 (2) and Pt-Cl = 2.318 Angstrom (2). The approximate linear azido l igands with N-alpha-N-beta-N-gamma-angles = 173.5-174.6 degrees are bonded with Pt-N-alpha-N-beta-angles = 116.4-121.0 degrees. In the vibrational spe ctra the PtCl stretching vibrations of (n-Bu4N)(2)[Pt(N-3)Cl-5] are observe d at 318-345, the PtN stretching modes of (n-Bu4N)(2)[Pt(N-3)(6)] at 401-42 8 and of (n-Bu4N)(2)[Pt(N-3)Cl-5] at 408-413 cm(-1) The mixtures (n-Bu4N)(2 )[Pt((NN2)-N-15)(n)((N2N)-N-15)(6-n)], n = 0-6 and (n-Bu4N)(2)[Pt((NN2)-N-1 5)Cl-5]/(n-Bu4N)(2)[Pt((N2N)-N-15)Cl-5] exhibit N-15-isotopic shifts up to 20 cm(-1). Based on the molecular parameters of the X-ray determinations th e vibrational spectra are assigned by normal coordinate analysis. The avera ge valence force constants are f(d)(PtCl) = 1.93, (f)d(PtNalpha) = 2.38 and f(d)((NNbeta)-N-alpha, (NNgamma)-N-beta) = 12.39 mdyn/Angstrom. In the Pt- 195 NMR spectrum of [Pt(N-3)(n)Cl6-n](2-), n = 0-6 downfield shifts with th e increasing number of azido ligands are observed in the range 4766-5067 pp m. The N-15 NMR spectrum of (n-Bu4N)(2)-[Pt((NN2)-N-15)(n)((N2N)-N-15)(6-n) ], n = 0-6 exhibits by N-15-Pt-195 coupling a pseudotriplett at -307.5 ppm. Due to the isotopomeres n = 0-5 for terminal N-15 six well-resolved signal s with distances of 0.03 ppm are observed in the low field region at -201 t o -199 ppm.