Metal donor to metal acceptor complexes. Fe(CO)42-, HFe(CO)4-, and trans-HFe(CO)3P(OMe)3- as anionic ligands to M(CO)50, M = Cr, W

Neighboring Metal-Induced Oxidative Addition in Conjunction with a Hydride Trap: Formation of [(η5-MeC5H4)Fe(CO)(μ-η1:η1-PPh2CH2PPh2)(μ-H)M(CO)4] (M = W, Mo)

“…Especially noted are the five CO ligands (originally two with Fe, three with W) now redistributed to one with Fe and four with W, the total remaining unchanged. The Fe−W distance, 3.185(2) Å, is about 0.2 Å longer than 2.989(2) Å found in [Ph 2 PNPPh 2 ] + [Fe(CO) 4 (μ-H)W(CO) 5 ] - , 11b, which has a formal Fe−W single bond. The torsion angle of Fe−P1···P2−W, 22.4(1)°, indicates that in 3a the metal centers are likely attractive whereas in 2a the metal centers are likely repulsive.…”

“…Outlined in Scheme , treatment of 1 (0.17 mmol) with M(CO) 5 (THF) (0.20 mmol) in THF (20 mL) at ambient temperature for 2 h yielded (η 4 -MeC 5 H 5 )Fe(CO) 2 (μ-η 1 :η 1 -dppm)M(CO) 5 , 2 ( 2a , 0.15 mmol, 88% yield; 2b , 0.13 mmol, 76% yield), after chromatographic workup on a silica column using 1:8 ethylacetate/ n -hexane as an eluent . Complex 2a revealed in its 1 H NMR spectra the characteristic peaks at δ 4.80 (2H), 2.58 (1H), and 2.07 (2H), consistent with a η 4 -MeC 5 H 5 bonding mode.…”

Versatile behavior of hydrido monometallic or heterobimetallic carbonyl anions toward dichlorophosphines and 1,1-dichlorodiphosphines

“…It has been shown that the reactions of dichlorophosphines RPC12 (R = Me, t-Bu, i-Pr2 N) with 2 equiv of la produce anionic phosphide complexes 11.2c n\pzH Fe/ xFe(CO)4 11We thought that with use of an anionic heterobinuclear complex such as 3 instead of la, a synthesis of heterobimetallic complexes of functionalized phosphides might be accessed. Darensbourg et al 3 have demonstrated that the hydride in 3 is attached to the more electronegative metal Fe and that there is no evidence of it every being transferred to the W(CO)5 unit. Indeed, all chemical reactions disruptive of 3 produce [HFe(CO)4]~a nd W(CO)5 fragments.…”

“…[Et4N][HW(CO)5], and [PPh4][HFeW(CO)9] were synthetized by published procedures. 3,11,12 Synthesis of (i-Pr2N)-P(Cl)-P(H)(N-i-Pr2)W(CO)5 ( 9). In a typical reaction, [Et4N]+[HW(CO)5]" (4.4 mmol) was added to a solution of the diphosphine 5 (4.4 mmol) in 5 mL of THF at -65 °C.…”

“…[Ph4P][HFe(CO)4] (la) which allows either the stabilization by complexation of short-lived phosphorus derivatives such as phosphinidenes, RP, diphosphenes, RP=PR, phosphacumulenes, RP=C=C<, phosphides, R2P", or the preparation of new phosphorus heterocycles difficult to obtain by conventional ways.1 2 Preliminary results have shown that the anionic tungsten hydrido carbonyl metálate [NEt4][HW(CO)5] (2) reacts similarly to la with phenyldichlorophosphine, PhPCl2, giving rise to the halogenophosphine complex PhP(H)-(Cl)W(CO)5 (4b).2a To our knowledge, similar work has been not undertaken with the anionic heterobinuclear complex [PPh4][HFeW(CO)9] (3). 3 The focus of the present work is to provide information concerning the reactions of 2 and 3 with dichlorophosphines or 1,1-dichlorodiphosphines and to compare their behavior with that of la. We report (i) the surprising difference of reactivity of 2 and [NEt4][HFe(CO)4] (lb) toward the diphosphine (i-Pr2N)2P-PCl2 ( 5), (ii) the X-ray diffraction studies of the new neutral or anionic functionalized diphosphine complexes, 9 or 10, and (iii) the versatile behavior of [Ph4P] [HFeW(CO)9] (3) which allows the synthesis of the anionic heterobimetallic phosphido complexes 14a-c, and 15a.…”