SYNTHESIS, STRUCTURES, AND EPR-SPECTRA OF THE RHENIUM(II) NITROSYL COMPLEXES [RE(NO)CL-2(PPH3)(OPPH3)(OREO3)], [RE(NO)CL-2(OPPH3)(2)(OREO3)], AND [RE(NO)CL-2(OPPH3)(3)](REO4)

The paramagnetic rhenium(II) nitrosyl, complexes [Re(NO)Cl-2(PPh3)(OPP h3)(OReO3)], [Re(NO)Cl-2(OPPh3)(2).(OReO3)], and [Re(NO)Cl-2(OPPh3)(3) ](ReO4) are formed during the reaction of [ReOCl3(PPh3)(2)] with NO ga s in CH2Cl2/EtOH. These and two other Re-II complexes with 5d(5) ''low -spin''-configuration can be observed during the reaction EPR spectros copically. Crystal structure analysis shows linear coordinated NO liga nds (Re-N-O-angles between 171.9 and 177.3 degrees). Three OPPh3 ligan ds are meridionally coordinated in the final product of the reaction, [Re(NO)Cl-2(OPPh3)(3)][ReO4] (monoclinic, P2(1)/c, a = 13.47(1), b = 1 7.56(1), c = 24.69(2) Angstrom, beta = 95.12(4)degrees, Z = 4). [Re(NO )Cl-2(PPh3)(OPPh3)(OReO3)] (triclinic <P(1)over bar>, a = 10.561(6), b = 11.770(4), c = 18.483(8) Angstrom, alpha = 77.29(3), beta = 73.53(3 ), gamma = 64.70(4)degrees, Z = 2) and [Re(NO)Cl-2(OPPh3)(2)(OReO3)] ( monoclinic P2(1)/c, a = 10.652(1), b = 31.638(4), c = 11.886(1) Angstr om, beta = 115.59(1)degrees), Z = 4) can be isolated at shorter reacti on times besides the complexes [Re(NO)Cl-3(Ph3P)(2)], [Re(NO)Cl-3(Ph3P ).(Ph3PO)], and [ReCl4(Ph3P)(2)].