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1968949 
Journal Article 
Chemistry of the azine phosphine ligand Z,E-PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4): crystal structure of [Mo(CO)(4){PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4)}] 
Shaw, BL; Perera, SD; Shenton, DJ; Thornton-Pett, M 
1998 
1 
Inorganica Chimica Acta
ISSN: 0020-1693
EISSN: 1873-3255 
270 
1-2 
312-325 
English 
WOS:000072720900039 
Condensation of Z-PPh2CH2C(Bu-t)=NNH2 with 4-nitroacetophenone gave the azine phosphine Z,E-PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4) (I). The corresponding phosphine oxide II was prepared by treatment of I with H2O2. The phosphine I with [Mo(CO)(4)(nbd)] (nbd = norbomadiene) gave [Mo(CO)(4){PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4)}] (1a); the corresponding tungsten 1b and chromium 1c complexes were made similarly. The crystal structure of 1a was determined by X-ray diffraction and showed the presence of a six-membered chelate ring with the bulky 4-nitrophenyl group held close to the metal. Oxidation of la with bromine gave the seven-coordinate molybdenum(II) complex 2, Treatment of [PtMe2(cod)] (cod = cycloocta-1,5-diene) with I at 20 degrees C gave the dimethylplatinum(II) complex [PtMe2{PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4)}] (3a) which with Mel gave the iodotrimethylplalinum(IV) complex 4. Treatment of 3a with C=O opened the chelate ring to give the dimethyl(carbonyl) platinum( II) complex 5 containing a monodentate phosphine ligand, When 3a was heated in toluene solution at 110 degrees C it gave the cyclometallated methylplatinum(II) complex [PtMe{PPh2CH2C(Bu-t)=N-N=CMe(C6H3NO2-4)}] (6). Treatment of 6 with Mel gave the platinum(IV) complex 7. The dichloropalladium(II) complex [PdCl2{PPh2CH2C(Bu-t)=N-N=CMe(C6H4NO2-4)}] (3b) was prepared by treatment of [PdCl2(NCPh)(2)] with I in CH2Cl2. Treatment of [PtCl2(NCMe)(2)] with 2 equiv, of I gave the trans-bis(phosphine) complex 8., When 2 equiv. of I were treated with [PtCl2(cod)] followed by NH4PF6 this gave the salt 9a containing two six-membered chelate rings; the analogous palladium(II) 9b salt was also prepared. Treatment of 2 equiv, of I with [PtCl2(cod)] followed by NH4PF6 gave the PF6 salt 10 containing a six-membered chelate ring and a monodentate ligand, When 10 was treated with AgNO3 followed by NH4PF6 this gave the bis-chelate complex II containing five and six-membered chelate rings, Treatment of [IrCl( CO)(2)(p-toluidine)] with I gave the cyclometallated iridium(III) hydride complex [IrHClCO{ PPh2CH2C(Bu-t)=N-N=CMe(C6H3NO2-4)}] (12). [RuCl2(PPh3)(3)] with the phosphine I resulted in the Ru(II) complex 13 in which the ortho hydrogens of the 4-nitrophenyl group are agostically interacting with ruthenium. Proton, phosphorus-31, some carbon-13 NMR and IR data have been obtained, Crystals of 1a are orthorhombic, space group Pna2(1),,with a = 1819.3(2), b = 1050.0( I),c = 1614.8(2) pm and Z=4; final R = 0.0191 for 2616 observed reflections, (C) 1998 Elsevier Science S.A. 
crystal structures; molybdenum complexes; azine phosphine complexes