Complexes 2e Research Articles

Synthesis of tetranuclear heterometallic cluster complexes via condensation of triosmium alkyne complexes OS 3(CO) 10(C 2R 2), R = Tol and Me, and mononuclear tungsten acetylide complexes LW(CO) 3)CCR′, L  Cp and Cp★, R′= Ph and tBu

Synthesis of tetranuclear heterometallic cluster complexes via condensation of triosmium alkyne complexes OS 3(CO) 10(C 2R 2), R = Tol and Me, and mononuclear tungsten acetylide complexes LW(CO) 3)CCR′, L  Cp and Cp★, R′= Ph and tBu

Four- and Five-Coordinated Nickel(II) Isocyanide Complexes and Donor–Acceptor Complexes Containing Nickel and Mercury

Abstract Reaction of NiI2(RNC)2 (1) (a: R=2,6-Me2C6H3; b; 4-Br-2,6-Me2C6H2; c: 2,4-t-Bu2-6-MeC6H2: d: 2,4,6-t-Bu3C6H2 with RNC or PPh3 gave NiI2(RNC)3 (2) or NiI2(PPh3) (RNC)2 (3) (a: R=2,6-Me2C6H3; b: 2,6-Me2-4-BrC6H2). An X-ray analysis of (3a) showed that the complex has a trigonal bipyramidal structure; crystal data: Space group Pna21; a=21.577(2), b=9.440(1), c=17.075(1) Å, α=β=γ=90.0°, V=3477.7(6) Å3, R=0.0444. The bromide and chloride complexes, NiX2(2,6-Me2C6H3NC)2 (1e: X=Cl; 1f: X=Br) did not produce five-coordinated species. When complexes (1a, 1b, 1e, or 1f) were treated with Hg in the presence of isocyanide, the donor–acceptor complexes [Ni(RNC)4HgX2]2 (X=I, Br, or Cl) (4) were formed. An X-ray analysis of (4b) (R=4-Br-2,6-Me2C6H2) was undertaken; crystal data: Space group: Pl (triclinic); a=12.709(3), b=16.145(3), c=12.614(3) Å, α=96.11(2), β=107.67(2), γ=73.11(2)°, V=2359.5(10) Å3, R=0.0686. The complex is a donor-acceptor complex containing the Ni–Hg bond and has a dimeric structure bridged by two I atoms. The configuration around Ni is the trigonal bipyramid and around Hg, distorted tetrahedron.

{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η2-ethen)nickel(O) und verwandte Verbindungen, Teil I

{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η2-ethene)nickel(0) and Related Compounds, Part II The coordinatively unsaturated (16e) (ethene)nickel(0) stannylene complex (C2H4)2Ni=Sn{CH(SiMe3)2}2 (1) reacts with 1,6-heptadiene with preservation of the Ni=Sn bond to yield quantitatively the 1,6-diene derivative (η2,η2-C7H12)Ni=Sn-{CH(SiMe3)2}2 (2). The alkene ligands of both 1 and 2 are readily displaceable. Compounds 1 and 2 react with butadiene at −50°C by a 4-e oxidation of the metal-metal pair Ni(0)/Sn(II) to Ni(II)/Sn(IV) and concomitant reduction of two butadiene molecules to butenediyl moieties to afford stereo-selectively the 16-e complex Ni-cis-{η3(Ni),η1(Sn)-anti-C3H4CH2}2Sn{CH(SiMe3)2}2 (3). Similarly, the reaction of 1 or 2 with isoprene yields regio- and stereoselectively the derivative Ni-cis-{η3(Ni,η1(Sn)-anti-C3(3-Me)H3CH2}2Sn{CH-(SiMe3)2}2 (4). These reactions imply the cleavage of one formal NiSn bond and the formation of two new SnC bonds. Upon reaction of 3 with PMe3 the configuration of the allyl system changes and, again fully stereoselectively, the 18-e addition compound (Me3P)Ni-cis-{η3(Ni),η1(Sn)-syn-C3H4-CH2}2Sn{CH(SiMe3)2}2 (5) is formed. When 5 is treated with BPh3, the phosphane ligand is trapped and, kinetically controlled, Ni-cis-{η3(Ni),η1(Sn)-syn-C3H4CH2}2Sn{CH(SiMe3)2}2 (6) is obtained as a stereoisomer of 3. At 40°C 6 slowly rearranges into the thermodynamically stable stereoisomer Ni-trans-{η3(Ni),η1(Sn)-syn-C3H4CH2}2Sn{CH(SiMe3)2}2 (7). Mild protolysis of 3 with pyridine hydrochloride or hydrobromide affords region and stereoselectively (Me3Si)2CH}2(X)SnNi-(η3-1-MeC3H4)(NC5H5) (X = C1, 8a; Br, 8b). In the course of this protonation reaction one butadiene molecule is eliminated, accompanied by a 2-e reduction of the metal-metal pair Ni(II)/Sn(IV) to Ni(II)/Sn(II) and, at the expense of two SnC bonds, reformation of a NiSn bond. All compounds are isolated in high yield and fully characterized by 1H-, 13C-, and 31P-NMR spectroscopy.

Reactions of the complexes Pt 3(μ-CO) 3L 3 with SO 2. Crystal structure of Pt 3(μ-CO) 3(P tBu 2Ph) 3·0.25(C 4H 8O)

Reactions of the complexes Pt 3(μ-CO) 3L 3, where LP tBu 3 ( 1a), P tBu 2 cPr ( 1b), P tBu 2Ph ( 1c), PCy 3 ( 1d) and PCy 2Ph ( 1e), with SO 2 have been examined. The complexes 1 may be divided into two classes: those complexes ( 1a, 1b and 1c) which fragment to yield a dimer Pt 2(μ-SO 2)(CO) 2L 2, where L=P tBu 3 ( 2a), P tBu 2 CPr ( 2b), P tBu 2Ph ( 2c), upon brief exposure to SO 2 and those complexes ( 1d and 1e) which substitute CO ligands with SO 2 ligands without a change in nuclearity to yield Pt 3(μ-SO 2) 3L 3, where L=PCy 3 ( 3d) and PCy 2Ph ( 3e). Traces of the complexes Pt 3(μ-SO 2)(μ-CO) 2L 3 (4) were observed after heating the complexes 2 under an SO 2 atmosphere for 14 h. As formation of dimeric products appeared to be favoured by larger ligands L, a method of evaluating the non-bonding interactions between the ligands L and the cluster fragment Pt 3(μ-CO) 3 was used to evaluate the size to the phosphine ligands. The X-ray crystal structure of the complex Pt 3(μ-CO) 3(P tBu 2Ph) 3 ( 1c) is reported.

Approaches to selective isoprenologation via reactions of (η 3-allyl)Fe(CO) +4 with allyl nucleophiles

The reactions of substituted (η 3-allyl)Fe(CO) 4BF 4 complexes 1 with various allyl-metals [M = SiMe 3 ( 2), -SnBu 3 ( 3) and -FeCp(CO) 2 ( 4)] and dienolate derivatives [CH 2 C(CH 3)CH COM(OR) (M = Li, SiMe 3)] have been investigated in search of a method for regio- and stereocontrolled allyl-allyl coupling. All three classes of allyl derivatives react with 1 in moderate to good yield with variable regioselectivity; the silyl derivatives 2 generally provide good regioselectivity for attack at the less substituted terminus of unsymmetrical derivatives of 1 but deprotonation of the 1,1-dimethylallyl complex 1e prevents efficient isoprenylation. Although deprotonation of 1e also dominates with the siloxydienes, the lithium dienolates couple efficiently with 1; however, reaction at the α position of the dienolate dominates.

Wasserlösliche Metallkomplexe und Katalysatoren, V. 2,2′‐Bipyridin‐5‐sulfonsäure und metallorganische Komplexe: Spektroskopie und Strukturchemie

Water‐Soluble Metal Complexes and Catalysts, V. — 2,2′‐Bipyridine‐5‐sulfonic Acid and Organometallic Complexes: Spectroscopy and StructuresCoplanar orientation of the pyridine rings in 2,2′‐bipyridine‐5‐sulfonic acid (1a) and in metal complexes of this ligand is evident from NMR studies. While the free acid 1a exists as a planar zwitter‐ion the rings of the salts 1b–d (Na+, [N(C4H9)4]+,[P(C6H5)4)]+) and sulfonamides 1f–h (tert‐butyl, benzyl, 2‐pyridylmethyl) are twisted. X‐ray crystal structures determined for four complexes 4e, h, 1, and 10b of the sulfonic acid and sulfonamide derivatives of 2,2′‐bipyridine show that there is no influence of the sulfonic acid and the sulfonamide groups (meta‐position) on the complex chemistry of the chelate ligand. Variation of solubility should, therefore, occur without principal changes of reactivity.

1,1-Difluorethen-Nickel-Ligand-Komplexe

The use of chelating ligands such as DCPE, BIPY and TMEDA as stabilizing ligands permits the preparation of the novel ligand-Ni complexes of 1,1-difluoroethene. The structures of the 16e complexes were confirmed by 1H, 13C, 19F and 31P NMR spectroscopy. Characteristic properties are described.

Synthesis and Morphology of New Discogenic Phthalocyanine Derivatives

Abstract New discogens based on the octasubstituted phthalocyanines (Pc) were synthesized: 2,3,9,10,16,17,23,24-octakis[dodecylthio-1-methyl]-phthalocyanine (1a), 2,3,9,10,16,17,23,24-octakis[4-(dodecylthio)-2-oxa-butyl]-phthalocyanine (1b), 2,3,9,10,16,17,23,24-octakis[dodecyloxy]-phthalocyanine (1c), phthalocyanine 2,3,9,10,16,17,23,24-octa-n-dodecanoate (1d), S-(+)-2,3,9,10,16,17,23,24-octakis[4-(dodecyloxy)-2-oxa-pentyl]-phthalocyanine (1e), as well as their corresponding copper complexes (CuPc) 2a, 2b, 2c and 2e. They were characterized by microanalysis, IR, 1H and 13C NMR spectroscopies, and their mesomorphic behaviors were examined with DSC and optical microscopic methods. The products exhibited the following optical textures and transition temperature ranges: focal conic (1a, 95-267°; 2a, 108-304°), linear default (1b, 52-247°; 2b, 70-255°; 1c, 75-269°; 2c, 78-310°), fan-shaped (1d, 58-303°; 2e, 29-191°). Chiral discogenic PcH2 1e, however, showed a cholestericlike texture (23-151°C) in which the ...

Hydration of polar organic molecules: the interaction of acetonitrile with water

The hydration of acetonitrile (1) is investigated by ab initio techniques at the 3-21G, 6-31G**//3-21G, and 6-31G**//6-31G** level of sophistication. Considered are 1:1 complexes formed between 1 and water. Hydrogen bonding to both the nitrile nitrogen (1a) and the bond of the nitrile moiety (1b) is investigated. 1b is found not to be a minimum on the 3-21G or 6-31G** potential energy surface. Water interacting with 1 via the methyl region is investigated by considering the possibility of C-H...O hydrogen bonding (1c) and bonding to the cavity formed by the three C-H bonds of the methyl group (1d). At the highest level of sophistication (6-31G**//6-31G**), 1c is not found to be a minimum on the potential energy hypersurface. A side-by-side complex (1e) in which water is oriented approximately parallel with the nitrile moiety is also considered. The interaction energies for these complexes at the 6-31 G**//6-31G** level of sophistication are as follows: 1a, 4.3 kcal/mol; 1e, 4.1 kcal/mol; 1d, 2.3 kcal/mol.

η1/η2-Isomerie bei Pentacarbonyl(thiobenzaldehyd)-Komplexen von Chrom und Wolfram

Abstract The benzylidene(pentacarbonyl) complexes of chromium and tungsten (CO)5M = C(H)R [M = Cr, R = C6H4OMe-P (2a); M = W, R = Ph (2b), C6H4CF3-p (2c)] react with SCN- inserting sulfur into the M = C bond to give (CO)5M[S = C(H)R] (3a-c). From the reaction of (CO5W=C(H)R [R = Ph (2h), 2,4,A-C6H2Me3 (2d), C6H4Me-p (2e)] with S8 in CH2Cl2 the thiobenzaldehyde complexes (CO)5W[S=C(H)R] (3b, d, e) are obtained. In 3a and 3d the thiobenzaldehyde ligand is η1-bonded. However, a dynamic equilibrium between the η1- and the η2-isomeric forms is observed for the complexes 3b, 3c and 3e. The equilibrium constant is dependent on the aryl group, the solvent and the temperature. In hexane the η2-isomer is favored by its lower enthalpy. Because of the small but positive entropy of the reaction η2-3→η1-3, increasing temperatures shift the equilibrium towards the η1-isomer.

Sandwich-Komplexe des Palladiums und Platins [1] / Sandwich Complexes of Palladium and Platinum [1

1,3,4,5-Tetraethyl-2-methyl-1,3-diborolene (1) reacts with MX2 (M = Pd, Pt) and Na(C5H5) to give orange-red cyclopentadienyl(1,3-diborolenyl)palladium 3 and the yellow platinum complex 4, respectively. Bis(1,3,4,5-tetraethyl-2-methyl-1,3-diborolenyl)platinum (5) is obtained in low yield from 1, Na(HBEt3) and PtCl2 or from 1 and [(C2H4)PtCl2]2. 1H, 11B, and 13C NMR data of 3, 4, and 5 are in agreement with a sandwich structure. The 16e complex 5 is reduced by potassium to its mono- and dianion.

The synthesis of a dinuclear anionic carbonyl derivative of manganese, [N(PPh3)2][Mn2(µ-PPh2)(CO)8], and its reactions with complexes of Group 1B and Group 8A metals to give mixed-metal clusters: comparative study of the X-ray crystal structures of [N(PPh3)2][Mn2(µ-PPh2)(CO)8], [Mn2{µ-Au(PMe2Ph)}(µ-PPh2)(CO)8], and [Mn2(µ-H)(µ-PPh2)(CO)8

The first anionic dinuclear carbonyl derivative of manganese, [Mn2(µ-PPh2)(CO)8]–, has been prepared by deprotonation of [Mn2(µ-H)(µ-PPh2)(CO)8](1) and isolated as its bis(triphenylphosphine)-iminium salt, [N(PPh3)2][Mn2(µ-PPh2)(CO)8](2). Complex (2) reacts with complexes of Group 1B and Group 8A metals to give the mixed-metal complexes, [Mn2(µ-ML)(µ-PPh2)(CO)8][M = Cu, L = PEt3(3a); M = Ag, L = PEt3(3b); M = Au, L = PMe2Ph (3c); M = Au, L = PPh3(3d); M = Au, L = PEt3(3e)], and [Mn2{µ-M(PPh3)L}(µ-PPh2)(CO)8][M = Rh, L = PPh3(4a); M = Ir, L = CO (4b)]. Complex (3e) ionises in solution in the presence of excess PEt3 to give [Au(PEt3)2]+ and [Mn2(µ-PPh2)(CO)8]–. The crystal structures of (2) and (3c) have been determined and are discussed in relation to that of (1), the structure of which has been redetermined in a different crystalline modification to that previously reported, and to a greater degree of accuracy than that originally achieved. Crystals of (1) are Triclinic, space group C, with a= 8.157(2), b= 19.246(3), c= 14.510(2)A, β= 89.10(3), β= 106.31 (3), γ= 90.07(3)°, Z= 4; 2 710 reflections with I 3σ(I)[3 < θ < 25°], refined to R= 0.0493 and R′, = 0.0506. Complex (2) crystallises in space group P21/c with a= 10.172(2), b= 30.441(4), c= 17.076(3)A, β= 100.88(3)°, Z= 4; 4 005 reflections [I 3σ(I), 3 < θ < 25°], refined to R= 0.067 and R′= 0.063. Crystals of (3c) are Monoclinic, space group P21/c, a= 13.360(2), b= 14.645(1), c= 17.336(3)A, β= 115.20(1)°, Z= 4; 1 843 reflections [I 2σ(I), 3 < θ < 22.5°], refined to R= 0.079 and R′= 0.065.

The Synthesis of New Cyclopentadienylruthenium Cyanide and Isocyanide Complexes

Abstract The syntheses of K[η5−C5H5Ru(CO)(CN)2] and its alkylation products η5−C5H5Ru(CO)(CN)(CNMe) and [η5−C5H5Ru(CO)(CNMe)2]I are reported. The latter has been converted to [η5−C5H5Ru(CNMe)3]PF6 via the isolated intermediate η5−C5H5Ru(CNMe)2I. The mixed ligand complex η5−C5H5Ru(CO)(PPh3)CN has also been prepared and alkylated to [η5−C5H5Ru(CO)(PPh3)(CNMe)]I. Infrared and 1H NMR characterization of each of the new compounds is included.

Reactions of bis(ethylene)(tertiary phosphine)platinum complexes with phenylethynyl derivatives of titanium and silicon; crystal structure of (µ-dimethylsilanediyl)(σ-phenylethynyl)[µ-(1-σ:1–2-η-phenylethynyl)]-bis(tricyclohexylphosphine)diplatinum (Pt–Pt)

Bis(ethylene)(tertiary phosphine)platinum complexes [Pt(C2H4)2(PR3)][PR3= P(cyclo-C6H11)3, PMe2Ph, PMePh2, PPh3, or PPri2Ph] react with bis(cyclopentadienyl)bis(phenylethynyl)titanium to give compounds [Pt{η-(PhCC)2Ti(η-C5H5)2}(PR3)] in which the PhCC–Ti–CCPh group acts as a bidentate ligand to platinum. In contrast, dimethylbis(phenylethynyl)silane reacts with [Pt(C2H4)2(PR3)][PR3= P(C6H11)3, PMeBut2, or PPri2Ph] to give diplatinum complexes [Pt2(σ-CCPh){µ-(1-σ:1–2-η-CCPh)}(µ-SiMe2)(PR3)2]. A single-crystal X-ray diffraction study has established the structure of the product from [Pt(C2,H4)2{P(C6H11)3}] and [Si(CCPh)2Me2]. Crystals are monoclinic, space group P21/c(no. 14), with a= 12.44(1), b= 26.12(4), c= 15.832(8)A, β= 97.99(6)°, and Z= 4. The structure has been determined by analysis of 5 131 unique data with F > 4σ(F) collected to 2θ⩽ 50°(Mo-Kα radiation) at 200 K on a four-circle diffractometer, and refined to R 0.053 (R′0.041). The results establish a molecular structure with an SiMe2 group asymmetrically bridging a Pt–Pt separation of 2.703(1)A. Two CCPh groups are σ-bonded to one metal atom (formally PtIV) but one is also η2-co-ordinated to the other platinum (formally PtII). The P–Pt–Pt–P skeleton is non-linear with PPtPt angles of 165.2(1) and 148.0(1)°. Dimethylbis(phenylethynyl)silane reacts with [Pt(C2H4)(PPh3)2], without carbon–silicon bond cleavage, to give mono- and di-platinum η2 complexes [Pt{η-PhCCSi(C2Ph)Me2}(PPh3)2] and [Pt2{η-(PhCC)2SiMe2}(PPh3)4].

Austauschreaktionen an komplexgebundenen Liganden von Elementen der V. Hauptgruppe, VI [1]. Lithiierung von η5-C5H5Mn(CO)2PH3 / Exchange Reactions at Complexed Ligands of Elements of Group Vb, VI [1]. Lithiation of η5-C5H5Mn(CO)2PH3

Abstract The metallation of η5 -C5H5Mn(CO)2PH3 with excess n-butyllithium and consecutive reactions with CH3I and (CH3)3SiCl yield the complexes η5 -C5H5Mn(CO)2PR3 (R = CH3, Si(CH3)3). The product of the lithiation is proposed to be η5-C5H5Mn(CO)2PLi3.

ChemInform Abstract: NIDO‐PENTABORANYL COMPLEXES OF CADMIUM

AbstractDie Komplexe (I) werden durch die Umsetzung von Dichloro‐bis‐[triphenylphosphin]‐Cd mit den K‐Salzen der entsprechenden Pentaboran‐Anionen dargestellt.

Nido-Pentaboranyl complexes of cadmium

The complexes [Cd(µ-B5H8)Cl(PPh3)] and [Cd(µ-1-BrB5H7)Cl(PPh3)] have been prepared by reaction of [CdCl2(PPh3)2] with the potassium salts of the appropriate pentaborane anions. On the basis of boron-decoupled 1H, proton-decoupled, 11B and 31P n.m.r. spectra the complexes have been shown to be non-fluxional, η2 complexes of the ligands [B5H8]– and [1-BrB5H7]–. The cadmium is formally a 16-electron species and the structure resembles that recently established by X-ray analysis for the ‘isoelectronic’ copper complex [Cu(µ-B5H8)(PPh3)2]. Attempts to prepare analogous complexes of zinc and mercury have been unsuccessful.