“…[Cr(C 27 H 26 P 2 )(CO) 4 ]ÁCH 2 Cl 2 M r = 661.38 Triclinic, P1 a = 8.9998 (5) Å b = 9.4895 (5) Å c = 18.3178 (9) Å = 99.811 (4) = 94.856 4= 93.020 (4) V = 1532.40 (14) Å 3 Z = 2 Mo K radiation = 0.69 mm À1 T = 150 K 0.50 Â 0.50 Â 0.27 mm Data collection: X-AREA (Stoe & Cie, 2005); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97. diphosphine complexes, of the type [M(CO) 4 {Ph 2 PC(R1R2)PPh 2 }] (M = Mo, W; R1 = H, Me, Et, Pr, allyl, R2 = Me, allyl), have been prepared via elaboration of the methylene backbones in [M(CO) 4 (Ph 2 PCH 2 PPh 2 )] (Ph 2 PCH 2 PPh 2 = dppm) as a result of successive deprotonation and alkyl halide addition (Hogarth & Kilmartin, 2007). The above mentioned chromium complex [Cr(CO) 4 (Ph 2 PCMe 2 PPh 2 )] was prepared also by this way, but not structurally characterized yet (Al-Jibori & Shaw, 1983).…”