Triphenylphosphin und Chloridionen bilden mit den Nitridchloriden des Molybdäns und Wolframs, MNCI3 (M = Mo, W) definierte Komplexe des Typs MNCl3 · P (C6H5) 3 sowie [MNCl5]2⊖, in denen Metall-Stickstoffmehrfachbindungen vorliegen. Die Verbindungen werden schwingungsspektroskopisch charakterisiert.
[MoCl4(NCl)]2 has been prepared by the reaction o f molybdenum hexacarbonyl with excess nitrogen trichloride in CCl4 solution; the product is a red, moisture-sensitive crystal powder. Decomposition above 100 °C leads to MoNCl3. According to the IR spectrum, [MoCl4(NCl)]2 is dimerized via chloro bridges, the group being linear.
Acetylene complexes of tungsten(IV) of the type [WCl4(RC≡CR)]2 (R = halogene, phenyl) react with tetrachloro-1,2-benzoquinone to give monomeric tungsten(VI) chelate complexes WCl2(O2C6Cl4)2 and W(O2C6Cl4)3, respectively. The complexes have been characterized by their IR and mass spectra.
Bis(tetrachloromolybdenum)diazene, [MoNCl4]2 is prepared by the reaction of molybdenum pentachloride with iodine azide as well as by the reaction of molybdenum pentachloride with nitrogen trichloride. The IR spectrum, the mass spectrum and the magnetic moment (μeff = 1.63 B.M.) are in agreement with a N-N-bonded dimeric structure and Mo ≡ N-triple bonds.
Osmiumpentachloride is prepared by the reaction of osmiumtetroxide with sulfur - dichloride. X-ray powder data gave identical results with those of other authors; however, the IR spectrum differs from the reported data. With AsPh4+Cl- in trifluortrichlorethane suspension the complex AsPh4[OsCl6] is formed, which can easily be reduced by dichloromethane to osmium(IV), forming the well known hexachloroosmate(IV), (AsPh4)2[OsCl6].
ReO3Cl with AICI3 and NbCls, respectively, forms the donor acceptor complexes
AlCl3 · ReO3Cl and NbCl5 • ReO3Cl. According to their IR spectra the complexes contain Re = O-Metal bridges. GaCl3 also forms a weak donor acceptor complex with ReO3Cl, which catalyzes the reaction of ReO3Cl with CCl4 forming COCl2
MoNBr2 is prepared by thermolysis of MoNBr3 in vacuo at 260 °C. It forms a dark brown hygroscopic powder; the IR spectrum indicates a MoN-multiple bond. The magnetic moment (μeff = 0.65 B.M.) is smaller than in undisturbed d1-systems, which is due to spin-spin-interaction. The monohydrate, MoNBr2 · H2O, can be identified by the mass spectrum.
The title compound has been prepared by the reaction o f [WCl4(NSeCl)]2 with PPh4Cl in CH2Cl2 solution. It forms red crystals, which were characterized by an X-ray structure determination. Space group P21/c, Z = 4, 3856 observed unique reflections, R = 0.073. Lattice dimensions at 25 °C: a = 2266.0(5), b = 1121.0(2), c = 2013.0(4) pm, β = 109.66(3)°. The structure consists o f PPh4+ ions and anions [WCl5(NSeCl2)]2-, in which the tungsten atom is surrounded in a distorted octahedral way by five chlorine atoms and by the nitrogen atom of the (NSeCl2)3- ligand. The W = N = SeCl2 group is characterized by WN and SeN double bonds; the selenium atom has a pseudo trigonal-bipyramidal coordination with the N atom and two lone pairs in equatorial and the chlorine atoms in axial positions.
[MONCl3 · NC - C2Cl3]2 has been prepared by the reaction of MONCl3 with trichloromethyl isocyanidedichloride, CCl3NCCl2 , in CH2Cl2 suspension. The compound forms redbrown. mois-ture sensitive crystals, which were characterized by their IR spectrum as well as by a crystal structure determination (2482 independent observed reflexions, R = 0.048). Crystal data (-70 °C): Space group P21/c, Z = 2, a = 674.2(2); b = 2128.2(11); c = 786.0(4) pm: β = 102.81(3)°. [MONCl3 • NC-C2Cl3]2 forms centrosymmetric dimeric molecules via chloro bridges with Mo-Cl bond lengths of 240.7 and 276.0 pm. The longer MoCl bond of the MOCl2MO ring is caused by the trans influence of the nitride ligand; the MoN bond length of 167 pm corresponds with a triple bond. The 2,3,3-trichloroacrylnitrile ligand is bonded by its nitrogen atom with a bond length of Mo -N = 216 pm; the Mo-N≡C-C sequence is almost linear with a remarkable short C-C bond of 143.0 pm.