Bis Bidentate Research Articles

Synthesis and spectroscopic characterization of new Cu(I) complexes containing triaryl-, tricycloalkylphosphines and heterocyclic anionic or neutral N-donor ligands. Crystal and molecular structure of [(Cy 3P) 2(pzH)Cu]ClO 4·CH 3OH (Cy=cyclohexyl, pzH=pyrazole)

The reaction of (PPh 3) 4CuClO 4, (PPh 3) 2CuCl, (Cy 3P) 2CuNO 3 and (Cy 3P) 2CuClO 4 with an excess of monodentate heterocyclic N-donor ligand (QH in general, in detail: ImH=imidazole, 1-MeimH=1-methylimidazole, 2-MeimH=2-methylimidazole, 4-Phim=4-phenylimidazole, BimH=benzimidazole, 1-BzimH=1-benzylimidazole, pzH=pyrazole, pz′H=3,5-dimethylpyrazole) in diethyl ether or benzene resulted in the formation of new 2:2:1 [(PPh 3) 2(QH) 2Cu]ClO 4 (QH=ImH, 1-MeimH, 2-MeimH, 4-PhimH, BimH, pzH) and [(PCy 3) 2(QH) 2Cu]NO 3 (QH=4-PhimH, BimH), 1:3:1 [(PPh 3)(1-BzimH) 3Cu]ClO 4, [(PCy 3)(1-MeimH) 3Cu]ClO 4 and [(PCy 3)(QH) 3Cu]NO 3 (QH=ImH, 1-MeimH, pzH), 2:1:1 [(PPh 3) 2O(QH)CuCl] (QH=ImH, 2-MelmH, 4-PhimH, BimH, 1-BzimH), [(PCy 3) 2 (QH)Cu]NO 3 (QH=1-BzimH, pz′H) and [(PCy 3) 2 (QH)Cu]ClO 4 (QH=2-MeimH, 4-PhimH, BimH, 1-BzimH, pzH, pz′H), 1:2:1 [(PCy 3)(2-MeimH) 2Cu]NO 3and [(PCy 3)(ImH) 2Cu]ClO 4 and 1:1:1 [(PPh 3) (1-MeimH)CuCl] adducts. With the bidentate donors bis(pyrazol)-1-yl)methane (L 1), bis(3,5-dimethylpyrazol-1-yl)methane (L 2) and bis(4-methylpyrazol-1-yl)methane (L 4), 2:1:1 [(PPh 3) 2(L)Cu]ClO 4 and 1:1:1 [(PCy 3)(L)Cu]ClO 4 complexes were obtained, whereas the exopolydentate bis (1,2,4-triazol-l-yl) methane (L 3) in similar conditions yielded 1:1:1 [(PPh 3)(L 3)Cu]ClO 4 and [(PCy 3)(L 3)Cu]NO 3, and 1:2:1 [(PCy 3)(L 3) 2Cu]ClO 4 derivatives. Breaking of the bridging C(sp 3)-N bond in the bidentate bis (pyrazol-1-yl)methane occurred when the reaction between L 1 and (PCy 3) 2CuNO 3 was carried out in diethyl ether under aerobic conditions, the derivative [(PCy 3)(pzH) 3Cu]NO 3 being formed. In methanol in the presence of base, ImH, 2-MeimH, 4-PhimH and BimH react with (PPh 3) 2CuCl giving the sparingly soluble complexes [(PPh 3) 2(Im)Cu]·1/2H 2O, [(PPh 3) 2(2-Meim)Cu]·H 2O, [(PPh 3)(4-Phim)Cu] and [(PPh 3)(Bim)Cu], respectively. Reaction of [(PPh 3) 2(ImH) 2Cu]ClO 4 with PCy 3, PBz 3 (Bz=benzyl), P( p-tolyl) 3, and (Ph 2PCH 2) 2 (abbreviated Diphos) resulted in the formation of compounds [(PPh 3)(PCy) 3(ImH) 2Cu]ClO 4, [(PPh 3)(PBz 3)(ImH)Cu]ClO 4, [(PPh 3)P( p-tolyl) 3(ImH) 2Cu]ClO 6 and [(Diphos) 2Cu]ClO 4, respectively, whereas reaction with 1,10-phenanthroline (Phen) and 2,2′-bipyridyl (Bipy) produced [(PPh 3) 2(ImH)(Phen)Cu]ClO 4 and [(PPh 3) 2(ImH)(Bipy)Cu]ClO 4, respectively. While PCy 3, PBz 3 and P( p-tolyl) 3 were not able to displace the triphenylphosphine from [(PPh 3) 2(L 1)Cu]ClO 4, Phen and Bipy in the same conditions formed the derivatives [(PPh 3) 2(Phen)Cu]ClO 4 and [(PPh 3) 2(Bipy)Cu]ClO 4. All of the complexes were characterized by IR and far-IR data, conductivity, 1H NMR and in some cases also with UV, 13C and 31P NMR and molecular weight measurements. The structure of [(Cy 3P) 2(pzH)Cu]ClO 4·CH 3OH was determined by single crystal X-ray diffraction: monoclinic, space group Pn,Z=2,a=9.949(7),b=13.128(4),c=16.588(8) A ̊ , β=91.15(7)° . The copper atom exhibited a distorted ideal trigonal planar geometry involving two phosphine groups (CuP:2.262(9) and 2.272(6) Å; PCuP: 132.3(7)°) and one pyrazole ligand (CuN:2.047(18)Å) coordinating through a pyridine-like nitrogen atom. The pyrazole donor of one molecule was hydrogen bonded to a molecule of methanol, which in turn was hydrogen bobded to the ionic perchlorato group.

Studies of Allylic Substitution Catalysed by a Palladium Complex of a C2‐Symmetric Bis(aziridine): Preparation and NMR Spectroscopic Investigation of a Chiral π‐Allyl Species

AbstractThe chiral palladium π‐allyl intermediate for the catalytic asymmetric synthesis shown in Scheme 1 has been isolated as the PF salt. MM 2 calculations have been performed and the structure of the palladium complex in solution has also been investigated by means of NMR spectroscopy. Both the computational and spectroscopic results suggest that in the complex the bidentate bis(aziridine) ligand adopts a conformation that forces the π‐allyl moiety out of the normally preferred square‐planar geometry. This nicely explains the very high enantioselectivity observed in the title reaction.

Synthesis and Characterization of Mononuclear Titanium Complexes Containing a Bis(phenoxy) Ligand Derived from 2,2′‐Methylene‐bis(6‐tert‐butyl‐4‐methylphenol)

AbstractA series of new titanium complexes of the general type Ti(mbmp)X2 (X = Br, I; OMe, OiPr, OtBu), containing a bidentate bis(phenoxy) ligand derived from 2,2′‐methylenebis(6‐tert‐butyl‐4‐methylphenol) (mbmpH2), was prepared. The 1H‐chemical shifts for the protons of the methylene link were found to vary considerably as a function of the ligand X. Reaction of Ti(OiPr)4 with two equivalents of mbmpH2 gave the C2‐symmetric spiro‐titanate complex Ti(mbmp)2. The crystalline labile solvent adducts of the dichloro complex Ti(mbmp)Cl2 with THF and DME were isolated and characterized. A single‐crystal X‐ray structural analysis revealed the THF adduct to be a mono(THF) adduct with a trigonal‐bipyramidal configuration, the bidentate mbmp ligand spanning an apical and equatorial site and the THF ligand occupying the remaining apical position.

A highly active palladium complex catalyst in the synthesis of N,N?-diphenylurea from nitrobenzene, aniline and carbon monoxide

A catalyst system comprising palladium acetate and bidentate bis(diphenylphosphino)alkane ligand of general formula Ph2P(CH2)nPPh2 (n = 3–5) was highly active in N,N′-diphenylurea synthesis from nitrobenzene, aniline and carbon monoxide and showed different reactivity from the system with the more common monodentate triphenylphosphine ligand.

Synthesis and X-ray crystal structure of μ-terephthalato nickel(II) binuclear complex [Ni 2(TPHA)(bpy) 4](ClO 4) 2

The X-ray crystal structure of the complex [Ni 2(TPHA)(bpy) 4](ClO 4) 2 (TPHA = terephthalato, bpy = 2,2′-bipyridine) has been determined. Its structure consists of a terephthalato bridged nickel(II) binuclear cation and non-coordinated perchlorate anions. In the complex the TPHA bridges are in a bis bidentate configuration. The environment of the nickel(II) ion is distorted octahedral.

Structure of (μ3-CCl)Co3(CO)7(μ-dppm); a chloroalkylidyne capped tricobalt cluster with a bidentate bis(diphenylphosphino)methane ligand bridging one edge of the tricobalt triangle

Structure of (μ3-CCl)Co3(CO)7(μ-dppm); a chloroalkylidyne capped tricobalt cluster with a bidentate bis(diphenylphosphino)methane ligand bridging one edge of the tricobalt triangle

ChemInform Abstract: Chelate Ring Opening and Metal Ion Relocation Leading to the Formation of a Luminescent AuIIrIAuI Chain Complex.

AbstractThe reaction of the monomeric Ir(I) complex (III) (space group Pbnb, Z = 8) containing bidentate bis(diphenylphosphinomethyl)phenylarsine ligands with the Au(I) chloride (IV) occurs with the unexpected opening of the little strained six‐membered chelate rings and bond reorganization to give the chain complex (V) (P1, Z=4).

Syntheses and properties of paramagnetic monocyclopentadienylmolybdenum(III) compounds with a four-legged piano-stool structure containing the bidentate bis(diphenylphosphino)ethane ligand

The MoCpX 2 (dppe) derivatives [Cp=η 5 -C 5 H 5 ; X=Cl, Br, I; dppe=bis(diphenylphosphino) ethane] have been obtained by interaction of MoX 3 (L-L)THF (THF=tetrahydrofuran) with TlCp and, for X=Cl, by reduction of MoCpCl 4 followed by treatment with dppe. The compounds have a low-spin configuration, as shown by EPR spectroscopy, and display a reversible oxidation to the corresponding 16-electron [MoCpX 2 (dppe)] + cations with respect to the internal FeCp 2 /FeCp 2 + couple. X-ray molecular structure of MoCpBr 2 (dppe)

Molybdenum and tungsten complexes of bidentate bis (aryldiazenato) ligands

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolybdenum and tungsten complexes of bidentate bis (aryldiazenato) ligandsRino A. Michelin and Robert J. AngeliciCite this: Inorg. Chem. 1980, 19, 12, 3850–3853Publication Date (Print):December 1, 1980Publication History Published online1 May 2002Published inissue 1 December 1980https://doi.org/10.1021/ic50214a055RIGHTS & PERMISSIONSArticle Views32Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (565 KB) Get e-Alerts Get e-Alerts