M.F. Perpiñán

Mono- and dinitrosyl complexes of molybdenum: crystal structure of molybdenum dinitrosyl bis(2-picolinate)

Abstract The reaction of the [Mo(NO)2]2+ moiety with the (X,Y)-donor ligands (X,Y = dithiocarbamates, xanthates, 2-picolinate, o-aminophenoxide, o-aminothiophenoxide or dithizone) leads fundamentally to formation of complexes of type Mo(NO)2(X,Y)2. Sometimes secondary products are also formed, as for example the mononitrosyl heptacoordinated complex Mo(NO)(2-pic)3 (5) (2-pic = 2-picolinate). In the reaction with dithizone a complex of composition Mo(NO)2(HDtz)2(H2Dtz) was isolated. The Mo(NO)2(R2dtc)2 (R2dtc = N,N-dialkyldithiocarbamates) complexes decompose in CHCl3 or by reaction with CO in CH2Cl2 to give the mononitrosyl derivatives Mo(NO)(R2dtc)3. The reaction of complex 6 with PPh3 yields Mo(2-pic)3·H2O. The crystal structure of Mo(NO)2(2-pic)2 has been determined. The crystals are orthorhombic, space group Pbca with a = 12.502(3), b = 15.15(4), c = 15.296(6) A, U = 2897(8) A3, z = 8, Dc = 1.84 g cm−3 μ(Mo-Kα) = 9.23 cm−1, F(000) = 1584. The Mo atom presents a distorted octahedral coordination. The atomic parameters have been refined by least-squares analysis of 1845 observed reflexions to R = 0.025.

Five-coordinate nickel(II) xanthate derivatives with triphos. Crystal structure of tris(O-cyclohexyldithiocarbonato)nickelate(II) of bis(2-diphenylphosphinoethyl)phenylphosphine-O-cyclohexyldithiocarbonatonickel(II)

Abstract Five-coordinate complexes, [Ni(S 2 COR)(TRIPHOS)]X (R = cyclo-C 6 H 11 , X = Cl, PF 6 , [Ni(S 2 COC 6 H 11 ) 3 ]; R = Et, X = PF 6 , [Ni(S 2 COEt) 3 ]), have been obtained by the reaction of O-alkyldithiocarbonato complexes, [Ni(S 2 COR) 2 ], with bis(2-diphenylphosphinoethyl)phenylphosphine (TRIPHOS). The structure of [Ni(S 2 COC 6 H 11 ) (TRIPHOS)][Ni(S 2 COC 6 H 11 ) 3 ] was determined by X-ray crystallography. The compound contains a five-coordinate cation and a hexa-coordinate anion. The geometry about the nickel atom in the [Ni(S 2 COC 6 H 11 )(TRIPHOS)] + is distorted trigonal bipyramidal with the axial positions occupied by one sulfur atom of the bidentate O-cyclohexyldithiocarbonate and the central phosphorus atom of the TRIPHOS. In the [Ni(S 2 COC 6 H 11 ) 3 ] − anion, the nickel atom is bonded to six sulfur atoms of three O-cyclohexyldithiocarbonate ligands. Formation of the dithiocarbonato complexes in the reactions of [Ni(S 2 COEt) 2 ] with TRIPHOS has also been observed.

Carbonyl complexes of molybdenum and tungsten with sulfur donors VI. Reactions of carbonyl complexes of molybdenum(0) and tungsten(0) with uninegative (S,X)-donor ligands (X = S, N, P)☆

Abstract The reactions of the zerovalent carbonyl complexes, M(CO) 6 , M(CO) 5 (Rpy), M(CO) 4 (Rpy) 2 (M = Mo, W, R = 2-Me, H) with a series of potentially mono- or bi-dentate uninegative (S,X)-donor ligands (S,X = xanthates, dithiocarbamates, pyridine-2-thiol, P,P -diphenyl- N -phenylphosphinothioformomido, P,P -diphenylphosphinedithioformamide) have given two types of anionic complexes: [M(S,X)(CO) 5 ] − and [M(S,X)(CO) 4 ] − (M = Mo 0 , W 0 ). These anions, which contain the (S,X)-ligand as a mono- or bi-dentate group, respectively, were isolated as their tetraphenylphosphonium or triethylammonium salts. Reactions of some of these species with allyl bromide and HgX 2 are described. The crystal structure of [PPh 4 ][W(S 2 COEt)(CO) 5 ] has been determined. The crystals are monoclinic, space group P 2 1 / n with a 14.555(4), b 12.44(1), c 17.950(2) A, U 3145.9(3) A 3 , Z = 4; D c 1.65 g cm −3 , μ(Mo- K α ) 39.68 cm −1 , F (000)_= 1544, R = 0.042 for 4278 observed reflections. In this complex the xanthate ligand is monodentate.

Reactivity of ruthenium complexes with uninegative (X,S)-donor ligands (X=S,P). II: Phosphine substitution in [Ru(S,S)2(PR3)2] derivatives, crystal structure of trans-bis(O-ethyldithiocarbonate)bis(dimethylphenylphosphine)-ruthenium(II)

Abstract The complexes [Ru(S,S)2(PPh3)2] [S,S  EtCOCS2−, (CH2)4NCS2−] react with a variety of tertiary phosphines with the substitution of triphenylphosphine and the formation of [Ru(S,S)2(PR3)2]. The reaction occurs with the formation ofthe cis isomer, except for the complex with PMe2Ph that gives rise to the trans isomer as the crystal structure shows. The effect of the different phosphines on the ruthenium complex is analysed in terms of the spectroscopic and electrochemical properties of the isolated compounds. The cyclic voltammetric studies of the cis complexes show that isomerization to the trans isomer occurs on oxidation. This isomerization is not observed in the trans-[Ru(S,S)2(PMe2Ph)2] complexes that give rise to stable trans-ruthenium(II)/ruthenium(III) couples. In a similar way the diphosphine complexes afford a quasi-reversible cis-ruthenium(II)/ruthenium(III) process.

Carbonyl complexes of molybdenum and tungsten with sulfur donors: V. Reactions of carbonyl complexes of molybdenum(0) with uninegative (X, Y)-donor ligands (X, Y = S, N, O)

Abstract The reactions of the zerovalent carbonyl complexes Mo(CO) 6 and Mo(CO) 4 (bipy) with a series of uninegative bidentate (X,Y)-donor ligands (X,Y = xanthates, dithiocarbamates, o -aminophenoxide, o -aminothiophenoxide, 2-picolinate and thioacetate) lead to new anionic tetracarbonyl complex anions [Mo 0 (X,Y)(CO) 4 ] − . These anions, which can be isolated as their tetraphenylphosphonium salts, contain the (X,Y)-ligand as a bidentate group. In the case of (X,Y) = monothioacetate the decarbonylated species [PPh 4 ][Mo II (TA) 3 ] is formed. The reacions of the new complexes with allyl bromide and methyl iodide are described.

Interactions of TCNQ in iron and nickel coordination compounds

The derivatives of formula [M(N-N) 3 ](TCNQ) x , (M= Fe, Ni; N-N= phen, bpy; x= 2, 4) have been obtained by reaction of the corresponding metal derivatives with LiTCNQ (x= 2) or NEt 3 H(TCNQ) 2 (x= 4). In the former the TCNQ units are dimerized by π overlap, except in [Fe(phen) 3 ](TCNQ-TCNQ) whose crystal structure shows the formation of a a dimer. The derivatives with four TCNQ per metal atom are good semiconductors and their magnetic behavior is typical of one-dimensional antiferromagnetic chains of S= 2 spins, localized on (TCNQ) 2 - units, and it could be fitted according to a one-dimensional Heisenberg antiferromagnet model..

Stabilization of TCNQ anion radical with di-and triamine complexes of nickel and copper

Abstract The reactivity of the organic acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ in its neutral or anionic radical forms with saturated di- and triamino derivatives of nickel and copper such as the cationic complexes with ethylenediamine, [M(en) 3 ] 2+ , trimethylenediamine, [M(tn) 2 (H 2 0) 2 ] 2+ , and diethylenetriamine, [M(dien) 2 ] 2+ , is discussed on the basis of the metal environment stability. The products obtained show either substitution of some labile ligands from the metal coordination sphere and σ-coordination of the anionic TCNQ or alternatively displacement of the counter-ion by anionic TCNQ with maintenance of the coordination around the metal. The complexes studied show the TCNQ groups forming dimeric, or trimeric, anionic associations with strong antiferromagnetic intradimer coupling between the radical units. The complex [Ni(dien) 2 ](TCNQ) 2 shows a weaker TCNQ-TCNQ coupling with a singlet-triplet equilibrium observable at temperatures above 60 K from its contribution to the total magnetic susceptibility of the complex.

Carbonyl complexes of molybdenum and tungsten with anionic chelating donors: VII. Tricarbonylphosphine complexes of molybdenum(0) and tungsten(0) with chelating uninegative (X,Y)-donor ligands (X, Y = S, N, O)☆

Abstract The reactions of zerovalent tricarbonylcomplexes M(CO)3L3 (M = Mo, L3 = C7H8, 3CH3CN, 3py; M = W, L = py) with a series of uninegative chelating (X, Y)-donor ligands (X, Y = xanthates, 2-picolinate, 2-quinaldinate and pyridine-2-thiolate) and trisubstituted phosphines, PR3 (R = Ph, 2-CH2CH2CN) lead to new anionic tricarbonyl complexes fac-[Cat][M(X, Y)(CO)3(PR3)] (Cat+ = PPh4+, Et3NH+, Et4N+, [Ni(phen)3]2+). No products were isolated from reaction of M(CO)4(PPh3)3 or M(CO)3(PPh3)3 with the (X,Y)-donor ligands. Treatment of the previously reported complexes, [Cat][M9X, Y)(CO)4], with PPh3 did not give phosphine derivatives. The new compounds have been characterized by IR and 1H, 13C and 31P-NMR spectroscopy.

X-ray crystal structure of [Ni(S2COC6H11)2(PMePh2)]. Asymmetric coordination of the O-cyclohexylxanthate ligand

Abstract The structure determination of [Ni(S2COC6H11)2(PMePh2)] shows the presence of one asymmetrically coordinating O-cyclohexylxanthate

Anionic tetracarbonyl 2-carboxypiridinato or 2-carboxyquinolinato of tungsten(O). reactions with mercury(II) derivatives

Abstract New anionic tetracarbonyl complexes, [W(N,O)(CO) 4 ] − , containing (N,O)-donor ligands (2-picolinate and 2-quinaldinate) have been isolated, and their reactions with HgX 2 (X = Cl, Br, CN) studied. The reactions give either anionic or neutral compounds, containing WHg bonds, of types [W(N,O)(CO) 3 (HgX)(X)] − (X = Cl, Br), [W(N,O)(CO) 3 (HgBr)] n , [Ph 4 P] 2 [>W(N,O)(CO) 3 } 2 (HgX 2 )] (X - Cl, CN) and [Ph 4 P][W(CN)(N,O)(CO) 2 Hg(CN) 2 ], depending on the reaction conditions.