J.E. Guerchais

Niobium organometallic chemistry : IX. CS2 complexes: synthesis, reactivity and their use as ligand; crystal structure of (n-C4H9)(ν5-C5H5)2Nb(μ-CS2)W(CO)5

Abstract Carbon disulphide reacts with niobium complexes [Nb(η-C5H5)2(Me)2] and [Nb(η-C5H5)2H (CH2CHC2H5)] to produce the new η2-CS2 derivatives [Nb(η-C5H5)2(Me)(η2-CS2)] (1) and [Nb(η-C5H5)2(Bu) (η2-CS2)] (2) respectively. Treatment of 1 and 2 with methyl iodide affords the respective cationic η2- dithioalkyl ester complexes [Nb(η-C5H5)2(Me) {η2-C(S)SMe}] I (3) and [Nb(η-C5H5)2(Bu) {η2-C(S)SMe}] I (4). Hetero-dinuclear complexes [(Bu)-(η-C5H5)2Nb(η-CS2)M(CO)n] (M  Cr, Mo, W; n  5. M  Fe; n  4) and [(Bu)-(η-C5H5)2Nb(μ-CS2)Mn(CO)2(η-CH3C5H4)] and an homodinuclear complex [(Bu)(η-C5H5)2Nb(μ-CS2)Nb(η-C5H5)2(Bu)] have been synthesized. The structure of the niobium—tungsten derivative has been determined by single-crystal X-ray diffraction. Crystal data are space group P21/c, a 12.935(4), b 12.742(4), c 14.565(4) A, β 103.27(3)°, Z  4. The Nb(μ-CS2)W unit is planar within ±0.06 A. The CS2 group is η2-bonded to niobium through a CS linkage and σ-bonded to manganese through the other sulfur atom. The 13C NMR spectra indicate that 2 has a larger σ-donor/π-acceptor ratio than CO.

Reactions de quelques cyclopentadienyl methanethiolato fer et ruthenium avec des acetylenes fluores. Mise en evidence d'une double insertion d'un carbonyle et d'un acetylene

[(η5-C5H5)(CO)2Fe(SCH3)] reacts with trifluoropropyne to give a number of products [(η5-C5H5)(CO)2Fe[CC(CF3)]], [(η5-C5H5)(CO)FeC(O)C(CF3)CHS(CH3)], [(η5-C5H5)(CO)FeC(CF3)CHS(CH3)Fe(CO)(η5-C5H5)S(CH3)], [(η5-C5H5)(CO)Fe[(CF3C2H)2SCH3]],[(η5-C5H5)(CO)2Fe[C(CF3)CHSCH3]], [(η5-C5H5)(CO)Fe[(CF3C2H)2S(CH3)]] and [(η5-C5H5)(CO)FeC(CF3)CHS(CH3)] and with hexafluorobut-2-yne to give [η5-C5H5)(CO)FeC(O)C(CF3)C(CF3)S(CH3)]], [(η5-C5H5)(CO)FeC(CF3)C(CF3)S(CH3)], [(η5-C5H5)Fe[η4-CF3C2CF3CF3C2HS(CH3)]] and [(η5-C5H5)(CO)Fe(CF3C2H)(CF3C2CF3)S(CH3)]. With the analogous ruthenium thiolate complex a compound [(η5-C5H5)(CO)RuC(O)C(CF3)C(CF3)S(CH3)] is obtained. Many of the products are heterocyclic compounds containing iron and sulphur. The acetylenic and carbonyl groups readily insert into FeSCH3 bonds and the resultant groups can undergo further insertion by acetylenes.

Bis-cyclopentadienyl molybdenum and tungsten compounds with mercury-transition metalmercury bonds. Part I. Chemical, spectroscopic and structural studies of halogeno- and thiolato-derivatives

Abstract Cp 2 MH 2 (M = Mo and W) react with HgX 2 (X = Cl, Br, I, SCN, OAc and CN) salts, giving insoluble compounds which have the general formula Cp 2 M(HgX) 2 ·xHgX 2 (I) (x = 0, 1 3 , 1 2 , 2 3 and 1). These compounds were characterized by using IR and, for some of them, Raman spectroscopy. Frequencies of Hg-X vibrations are discussed in the light of an ‘adduct type’ structure. MoHg and WHg bands are detected in the Ramam spectra near 130–140 cm −1 . An intermediate polymeric compound (Cp 2 MoHg) n (II) was isolated and characterized by IR spectrum and unit cell parameters. All compounds (I) and (II) react with thiolates giving non-adduct: i) compounds Cp 2 M(HgSR) 2 (R = Me, Et, i Pr and n Pr) (III) soluble in organic solvents and ii) insoluble compounds [Cp 2 MHg 2 (SR)]X(X = Cl, Br) (IV). Compounds (IV) with X = Cl also crystallize from solutions of (III) in chloroform. Insoluble Cp 2 M(HgSR) 2 (R = pheynl or pyrimidine) compounds were obtained by the reaction of (I) with corresponding thiolates. IR spectra of all these derivatives were recorded showing similar features to those of the compounds (I). ( 1 H), ( 13 C) and ( 99 Hg) NMR spectra of soluble complexes (III) were recorded. The structure of [Cp 2 MoHg 2 (SEt)] Cl determined by X-ray analysis is built of infinite chains of Cp 2 MoHg 2 moieties and thiolates bridging two mercury atoms from the adjacent Cp 2 MoHg 2 units and of essentially ionic chlorides.

Reactivite d'alcynes fluores vis-a-vis de methylthiolates [(η5-C5H5)M(SMe)(CO)3] et d'hydrures [(η5-C5H5)MH(CO)3] de molybdene et de tungstene

Abstract The electron deficient acetylene, hexafluorobut-2-yne, reacts with molybdenum and tungsten methanethiolate derivatives (prepared in situ) to give vinyl and three-, five-, or six-membered heterocyclic derivatives: [Cp(OC)- MoC(O)C(CF 3 )C(CF 3 )C(O)S Me], [Cp(OC)2 MC(CF 3 )C(CF 3 )C(CF 3 )C(O)S Me], [CpW(CO)3C(CF3C(CF3)SMe], [CpW{η3- C(CF 3 )C(CF 3 )C(SMe)OC (O)}-(CO)2]. These reactions contrast with those of trifluoropropyne where no organometallic species are obtained. On heating or irradiation with CF3CCCF3 [CpMH(CO)3] gives known bridged species and in the presence of dimethyl disulphide the vinyl derivative [CpM(CO)3C(CF3)C(CF3)H]and an isomer of undetermined structure.

Transition metal-cyanocarbon chemistry: IX. Reactions of monocyanoacetylene with dicarbonylcyclopentadienylmethylthiolatoiron(II). Crystal structures of [FeC(O)C(CN)CH(SCH3) (η5-C5H5)(CO)] and of μ-η2-Fe(CCCN)(η5-C5H5)(CO)2][Co(CO)3]2

Abstract The reaction of [Fe(η5-C5H5)(SCH3)(CO)2] with monocyanoacetylene (HCCCN) in THF at room temperature gives the acetylide [Fe(CCCN)(η5-C5H5)(CO)2] (1, the acylic species [ FeC(O)C(CN)CH(S CH3)(η5-C5H5)(CO)] (2), the binuclear complex [Fe(η5-C5H5)(CO)2C(CN)C(SCH3)Fe(η5-C5H5)(CO)2] (3), and the disubstituted olefin Z-(NC)CHCH((SCH3) (4. If the HCCCN is condensed on to a frozen solution of the thiolato complex and the mixture then allowed to warm up, the acylic compound 2 is not isolated. Irradiation of 1 and 3 in the presence of PPh3 in THF gives the substituted complex [Fe(CCCN)(η5-C5H5)(CO)(PPh3)] (6)_and [Fe(η5-C5H5)(CO)2C(CN)C(SCH3)Fe(η5-C5H5)(CO)(PPh3)] (10). Cycloaddition of tetracyanoethylene on 1 and 6 gives the corresponding complexes [fe( CC(CN)C(CN) 2 C (CN)2(η5-C5H5)(CO)(L)] (L = CO (7) or PPh3 (8). Under UV irradiation 8 is converted into Fe(η 3 -C(CN) 2 C(CN)C C(CN)2(η5-C5H5)(PPh3)] by loss of CO. Complex 1 reacts with Co2(CO)8 to form the [μ-η2-Fe(CC-CN)(η5-C5H5)(CO)2][Co(CO)3]2 (5). The structures of 2 and 5 have been determined by X-ray diffraction.

Molybdenum alkyl- and aryl-thiolates

Abstract The reaction between [(η 5 -C 5 H 5 )MoH(CO) 3 ] and disulphides gives dimeric or trimeric complexes depending upon the conditions. The syntheses of the novel trinuclear molybdenum carbonyl complex [{Mo(η 5 -C 5 H 5 )(SR)(μ-CO)(CO)} 3 ] (R = Me), and dinuclear compounds [Mo 2 (η 5 -C 5 H 5 )(μ-SR) 3 (CO) 4 ] (R = Me) and [Mo 2 (η 5 -C 5 H 5 ) 2 (SR) 2 (CO) 2 (μ-SR)(μ-Br)] (R = Me or Ph) are reported.

Transition metal-cyanocarbon chemistry: VII. Reactions of mono- and di-cyanoacetylenes with tricarbonylcyclopentadienylmethylthiolatotungsten(II). Formation of phosphorus ylide complex [(C5H5)(CO)2W(CH(P(C6H5)3)C(CN)SCH3)]. Crystal structure of [(C5H5)(CO)2(P(C6H5)3)-W(C(O)C(CN)CHSCH3)·CH2Cl2]☆

Abstract Reactions of (C 5 H 5 )(CO) 3 W(SMe) with cyano-activated alkynes RCCCN with R  H or CN give heterometallacyclic complexes (C 5 H 5 )(CO) 2 W(C(O)C(CN)C(R)S Me) (R  H ( 2 ) or CN ( 6 )) or for R  H, an insertion σ-vinylic complex [(C 5 H 5 )(CO) 3 W(CHC(CN)SMe)] ( 3 ). Irradiation of 3 in the presence of PPh 3 in THF gives the ylide complex (C 5 H 5 )(CO) 2 W(η 2 -CH(PPh 3 )C(CN)SMe) ( 5 ), whereas 2 under such conditions gives an η 1 -acylic complex [(C 5 H 5 )(CO) 2 PPh 3 W(C(O)C-(CN)CHSMe)] ( 4 ). The structure of 4 has been determined by X-ray diffraction.

Transition metal-cyanocarbon chemistry X. Reactions of monocyanoacetylene and dicyanoacetylene with organometallic compounds of cobalt(I) and nickel(II). Crystal structure of [Co(CCCN)2(η5-C5H5)(P(C6H5)3)]☆

Abstract The reaction of monocyanoacetylene (HCCCN) with [Co(η 5 -C 5 H 5 )(P(C 6 H 5 ) 3 ) 2 ] gives the vinylacetylide [Co(CCCN)(CHCH(CN))(η 5 -C 5 H 5 )(P(C 6 H 5 ) 3 )] ( 1 ) and the diacetylide [Co(CCCN) 2 (η 5 -C 5 H 5 )(P(C 6 H 5 ) 3 )] ( 2 ). The crystal structure of the latter has been established by an X-ray diffraction study. Two conformers of 1 are formed in a ratio depending on conditions. In 1 a PPh 3 ligand can be replaced by (CH 3 ) 3 SiCCSi(CH 3 ) 3 , which acts as a π-bonded ligand in the product, [Co(CCCN)(CHCH(CN))(η 5 -C 5 H 5 )(η 2 -(CH 3 ) 3 SiCCSi(CH 3 ) 3 )] ( 3 ). Treatment of 1 with I 2 gave (Co(η 5 -C 5 H 5 )(I) 2 (P(C 6 H 5 ) 3 )] ( 6 ) and CH(CN)CH-C(CN)CHI ( 5 ). The major product of the reaction of [Co(η 5 -C 5 H 5 )(P(C 6 H 5 ) 3 ) 2 ] with dicyanoacetylene (NCCCCN) was the 1,6-diphosphorane (C 6 H 5 ) 3 PC(CN)C(CN)C(CN)C(CN)C(CN)C(CN)P(C 6 H 5 ) 3 . [Co(η 5 -C 5 H 5 )(η 4 -C 5 H 5 (CCCN))] ( 7 ) was isolated from the reaction of monocyanoacetylene with [Co(η 5 -C 5 H 5 )(η 4 -C 5 H 6 )]. Cyanoalkynes bridge two nickel atoms in [μ-(HCCCN)][Ni(η 5 -C 5 H 5 )] 2 ( 8 ) and [μ-(NCCCCN)][Ni(η 5 -C 5 H 5 )] 2 ( 9 ), which were formed in the reaction of nickelocene with HCCCN and NCCCCN, respectively.

Reactions of fluorinated alkynes with the tungsten Hydride [(η5-C5H5)(CO)3WH] II. Phosphine and phosphite substitution reactions and the x-ray structures of the η3-acryloyl complexes [(η5-C5H5)(CO)LWC(O)C(CF3)C(CF3)H], L = CO, P(OMe)3

Abstract Insertion of hexafluorobut-2-yne into the WH bond of the complex [(η5-C5H5)(CO)3WH] yields the η1-vinyl complex [η5-C5-C5H5)(CO)3WC(CF3)C(CF3)H] (I). Migration and insertion of CO into the metal-vinyl bond gives the η3-acryloyl complex [(η5-C5H5)(CO)2 WC(O)C(CF 3 ) C(CF3)H] (II) for which the crystal structure has been determined. Phosphites and phosphines (L = P(OMe)3, PPh3, PMe3, PMe2Ph, PPh2H) displace CO from II to give IIIa in which the η3-acryloyl structure is conserved and CO is adjacent to the acryloyl carbonyl group, as shown by an X-ray analysis of IIIa1, the product with P(OMe)3. Heating IIIa generates the η1-vinyl complexes [(η5-C5H5 )(CO)2 LWC(CF3)C(CF3)H] (IV) whereas prolonged photolysis of IIIa yields isomeric η3-acryloyl compounds (IIIb) in which the phosphorus donor ligands are now adjacent to the acryloyl carbonyl groups.

New observations on dicyclopentadienylmolybdenum complexes derived from dimethyl acetylenedicarboxylate. Crystal structure of [(η5-C5H5)2MCO2CH3]

Abstract Addition of chloroform to a solution of (η 5 -C 5 H 5 ) 2 MoH 2 and dimethylacetylenedicarboxylate (CH 3 CO 2 CCCO 2 CH 3 ) in THF at 0°C gives two new complexes: (i) chloro-αs-alkenyl (η 5 -C 5 H 5 ) 2 MoCl[Z-C(CO 2 CH 3 )CH(CO 2 CH 3 )] and (ii) metallacyclic [(þ 5 -C 5 H 5 ) 2 M oOC(O)CHC CO 2 CH 3 ]. An X-ray diffraction study of the latter product revealed the presence of one water molecule per one organometallic molecule in the unit cell: space group P 2 1 , a 12.111(9), b 7.374(2), c 7.830(5) A, β 93.43(4)°, Z = 2. The MoC bond length is 2.180(6) A. A mechanism involving an intramolecular elimination of CH 4 from the initially formed insertion product (η 5 -C 5 H 5 ) 2 MoH[Z-C(CO 2 CH 3 )CH(CO 2 CH 3 )] is proposed for its formation.