Rhodium, nitrosyltris

Acetic acid (1.0 mL) is added to nitrosyltris(triphenylphosphine)rhodium (0.4 g), and then acetone (25.0 mL) is added. The red suspension is stirred in air for 25 min during this time the suspension darkens, turns green, and deposits a green precipitate. This precipitate is filtered off, washed successively in acetone (2 x 10 mL), water (2 x 10 mL), and acetone (2 x 10 mL), then dried in vacuo. 

Nitrosyltris(triphenylphosphine)rhodium(I) was first prepared, in admixture with [Rh(NO)Cl2(PPh3)2], by allowing excess triphenylphosphine to react with [Rh(NO)2Cl] in tetrahyd-rofuran.1299 Since that time four other preparative methods, shown in Scheme 41, have been devised.199,201,202 1300-1303 Of these methods that using AT-methyl-AT-nitrosotoluene-p-sulfonamide is the most convenient.199 201 202 The dark crimson-red crystals of the complex start to decompose at 115 °C in air, but at 225 °C in a helium atmosphere.180... 

Tertiary phosphine analogs have been prepared from [Rh(NO)2Cl]x.1301 Nitrosyltris(phosphorus trifluoride)rhodium has been prepared from both rhodium(—I) and rhodium(I) complexes (equations 294-296).1297 Their physical properties are listed in Table 90. The triphenylphosphine complex is quite reactive (Scheme 42). Both electronic1312 and 31P NMR spectrometry show the equilibrium constant for the reaction (297) to be of the order of 10-4moldm3 in dichloromethane, benzene1312,1313 or THF,1313 so the reactivity of the complex cannot arise from the facile loss of a... 

Nitrosyltris(triphenylphosphine)rhodium has previously been prepared by sodium-amalgam reduction of a mixture of rhodium nitrosyl chloride and triphenylphosphine in tetrahydrofuran.32 Preparations from hydridotetrakis(triphenylphosphine)rhodium(I) and nitric oxide,24 and from rhodium trichloride, nitric oxide, triphenylphosphine, and zinc dust have also been reported.35 The following synthesis1 is convenient and rapid. 

Nitrosyltris(triphenylphosphine)rhodium forms bright crimson-red microcrystals. It softens at 96°, then melts with decomposition at 160° in air sealed under nitrogen it melts at 205-206°. The infrared spectrum shows a peak at 1610 cm.-1 (vs) attributed to v(NO). The complex is soluble in dichloromethane, chloroform, and benzene. 

C5 ftHft glrNOPa, Tris(triphenylphosphine)nitrosyliridium, 37B, 666 C5 ftHft gNOPaRh, Nitrosyltris(triphenylphosphine)rhodium, 43B, 1466 CgftHft gNi02P3S, (Sulfur dioxide)tris(triphenylphosphine)nickel(0), 45B, 1380... 

---