cis-Tetracarbonylbis(triphenyl phosphite)molybdenum(0)

Versatile Phosphite Ligands Based on Silsesquioxane Backbones

“…The 31 P NMR spectrum showed a singlet at d 80.3 ppm, together with 195 Pt satellites and a coupling constant J Pt-P of 4680 Hz, which is characteristic for two phosphites coordinated in a trans-fashion. [24] By slow diffusion of CH 3 CN into a CH 2 Cl 2 solution of this compound, single crystals could be grown that were suitable for X-ray analysis.…”

“…As expected, the 13 C NMR spectrum of compound 2 reflected the 1 : 3 : 3 ratio between the ipso- carbons of the cyclopentyl groups, indicative of a C 3v symmetry for the obtained product. In the corresponding 31 P NMR spectrum a singlet was present at d 132.6 ppm, which is a normal chemical shift value for phosphites. Very recently, the group of Edelmann published the synthesis of a phosphorus diamide based on the same structural skeleton as present in 1 and 2, by reaction of the monosilanol shown in Scheme 1 with P(NMe 2 ) 3 .…”

“…These values agree reasonably well with other cis-Mo(CO) 4 (phosphite) 2 complexes. [29,30] In the 31 P NMR spectrum of the crude reaction mixture a singlet was observed at d 149.6 ppm together with a minor peak at d 131.3 ppm indicating the small excess of free ligand. To get a confirmation of the actual coordination of the ligand to the molybdenum atom, a crystallographic study was undertaken, since single crystals could be grown by slow diffusion of acetonitrile into a dichloromethane solution of Mo(CO) 4 (3).…”

“…Complexation of 3 with PdCl 2 (cod) at room temperature resulted in a fine yellow powder and the 31 P NMR spectrum showed a singlet at d 88.9 ppm (Scheme 4). From this finding alone, no conclusion can be drawn as to which isomer is formed.…”

trans-Tetracarbonylbis(tri-tert-butyl phosphite)molybdenum(0)

“…NMR spectroscopy (Alyea & Song, 1995a,b;. The effects of changes in the P substituent (Y) and the degree of carbonyl substitution have previously been studied by the X-ray analyses of cis-[Mo(CO)a{P(C6H4-F-p)3}2] (Alyea, Ferguson, Gallagher & Song, 1994), cis-[Mo(CO)a{P(OPh)3}2] (2) (Alyea, Ferguson & Zwikker, 1994) and fac-[Mo(CO)3{P(OPh)3}3] (Alyea, Ferguson & Song, 1995). A search of the October 1994 release of the Cambridge Structural Database (Allen, Kennard & Taylor, 1993) revealed the absence of any other trans-Mo(CO)aP2 fragments involving phosphite ligands.…”