36491-17-5Relevant academic research and scientific papers
Syntheses and reactions of WH(CO)2(NO)(P(C6H5)3)2 and related tungsten nitrosyl complexes
Hillhouse, Gregory L.,Haymore, Barry L.
, p. 1876 - 1885 (2008/10/08)
cis-W(CO)4(PPh3)2 (1c) or trans-W(CO)4(PR3)2 (1t) (R = C6H5, p-CH3C6H4) reacted with NOPF6 in methylene chloride to give cis,mer-[W(CO)3(NO)(PR3)2][PF6] (2-PF6); BF4- and ClO4- salts (2-BF4; 2-ClO4) were also prepared. Halide anions (X = Cl-, Br-, I-) reacted with 2 first to give mer-WX(CO)3(NO)(PPh3) (7a, X = Cl; 7b, X = Br; 7c, X = I) and PPh3, then cis,cis-WX(CO)2(NO)(PPh3)2 (6a, X = Cl; 6b, X = Br; 6c, X = I), and finally trans,trans-WX(CO)2(NO)(PPh3)2 (3a, X = F; 3b, X = Cl; 3c, X = Br; 3d, X = I). Further reaction of 3c with NOPF6 and n-Bu4NX gave WXBr(NO)2(PPh3)2 (4c, X = Br; 4f, X = F). Upon reaction with NO+, trans-Cr(CO)4(PPh3)2 gave good yields of trans-[Cr(CO)4(PPh3)2][PF6] (5), but trans-Mo(CO)4(PPh3)2 produced complex mixtures. Acetate reacted with 2 to form trans,trans-W(η1-CH3CO2)(CO) 2(NO)(PPh3)2 (8) and then trans-W(η2-CH3CO2)(CO)(NO)(PPh 3)2 (11) and CO. Dimethyldithiocarbamate reacted with 2 to form cis-W-(η2-S2CNMe2)(CO) 2(NO)(PPh3) (13) and PPh3 and then trans-W(η2-S2CNMe2)(CO)(NO)(PPh 3)2 (14). In the presence of LiBH4 and PPh3 in tetrahydrofuran, both 3c and 2 were transformed into the tungsten(0) hydride trans,trans-WH(CO)2-(NO)(PPh3)2 (15). This hydride underwent α-insertion reactions with RN3 and RN2+, forming trans-W(η2-RN3H)(CO)-(NO)(PPh3)2 (19a, R = Ph; 19b, R = To) and trans,trans-[W(RN2H)(CO)2(NO)(PPh3) 2]+ (23, R = Ph; 24, R = To), and it underwent β-insertion reactions with RNCNR, CO2, and CS2, forming trans-W(η2-RNCHNR)(CO)(NO)(PPh3)2 (21, R = To), trans,trans-W(η1-HCO2)(CO)2(NO)(PPh 3)2 (9), and trans,trans-W(η1-HCS2)(CO)2(NO)(PPh 3)2 (22). Heating the hydride with RN=NNHR and RN=CHNHR produced trans-W(η2-RN3R)(CO)(NO)(PPh3)2 (20) and 21, respectively. When allowed to react with acids (HX; X = Cl, Br, I, CH3CO2, HCO2, OClO3), 15 gave trans,trans-WX(CO)2(NO)(PPh3)2 (3b, 3c, 3d, 8, 9, 16 (X = OClO3)). The perchlorato ligand in 16 was rapidly displaced by halide and pseudohalide anions but not by CO even at 1000 psi (20-80°C).
Relative phosphorus ligand sizes from cis:trans distributions of W(CO)4(L)(L′) products obtained from the reaction of W(CO)4(L) (py) with L′ (L and L′ = phosphines), reaction kinetics, and syntheses of starting materials
Boyles, Melissa L.,Brown, Daniel V.,Drake, Dennis A.,Hostetler, Cheryl K.,Maves, Constance K.,Mosbo, John A.
, p. 3126 - 3131 (2008/10/08)
The relative sizes of 12 phosphines (L′ = PMe3, PPhMe2, PEt3, P(n-Bu)3, PPh2Me, PPh2Et, PPh3, P(p-tol)3, PPh2(i-Pr), PPh2(t-Bu), PBz3, or PCy3) have been studied by determining cis:trans ratios of W(CO)4(L)(L′) products obtained from reactions of W(CO)4(L)(py) complexes with L′ (L = PPhMe2, PPh2Et, or P(p-tol)3). In general, a decrease in the cis:trans ratio was observed as the Tolman cone angle of L′ increased. Exceptions occurred with PEt3 and P(H-Bu)3, for which cone angles of 140-145°, rather than Tolman's value of 132°, would be consistent with the other ratio data. Kinetic studies of these reactions indicate that dissociative loss of pyridine is rate limiting. Also reported are the synthesis of W(CO)4(L)(py) from W(CO)4(py)2 and L and 31P NMR data for 21 new W(CO)4(L)(L′) complexes.
STERIC EFFECTS OF PHOSPHORUS LIGANDS: cis/trans DISTRIBUTIONS OF W(CO)4L2 PRODUCTS
Ounapu, Lois M.,Mosbo, John A.,Risley, John M.,Storhoff, Bruce N.
, p. 337 - 342 (2007/10/02)
The cis/trans product distribution in the reaction of phosphines with W(CO)4(Me2N(CH2)3NMe2) depends on ligand size; the smaller the ligand the greater the cis/trans ratio.The ratios range from 2.9 to 0 for PPh2Me and P(o-Tol)3, respectively.
