438 research outputs found
A Seven-Membered Platinum-Amino-Amidine Metallacycle. X-ray Structure of cis-[Pt(NH=CPhNButCH2CH2NHBut)Cl2]. ́Me2CO
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FACILE BENZENE-RING CONTRACTION TO CYCLOPENTENE DERIVATIVES DURING THE COPPER PROMOTED OXIDATION OF PHENOL WITH DIOXYGEN
No full textThe oxidation of phenol with dioxygen in the presence of copper metal, primary alcohols and pyridine, under mild conditions, produces new compounds deriving from the aromatic ring contraction (alkyl 1-hydroxy-2-oxo-4,5,5-trialkoxycyclopent-3-ene-1-carboxylate 2) which were characterized by H-1 and C-13-NMR. In particular an X-ray study of the methyl derivative is reported
Nucleophylic attack of amine and hidroxide to platinum-dichlorobenzonitrile. Crystal structure of [Pt(NH=CPhNButCH2CH2NHBut)Cl(NHCOPh)], 2, and cis [Pt(NH=CPhNButCH2CH2NHBut)Cl2(NCPh)], 3
No full textThe trans and cis isomers of [PtCl2(NCPh)2] react with N,N′-di-tert-butylethylenediamine (t-Bu2en) under normal conditions to give [Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl(NCPh)]Cl (1) and cis-[Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl2(NCPh)] (3), respectively. In both cases one end of t-Bu2en adds to benzonitrile forming an amino-amidine ligand which is chelated in 1 (forming a seven-membered metallacycle) and monocoordinated in 3. The residual benzonitrile in the cationic complex 1 readily reacts with base to give a benzamidate species, [Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl-(NHCOPh)] (2). Compound 3 exhibits, in solution, isomerization about the azomethine double bond (Δ‡223 = 10.8 ± 0.3 kcal mol-1) and more slowly undergoes an internal rearrangement with substitution of the residual benzonitrile by the uncoordinate end of the diamine and formation of [Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl2] (4). The structures of 2 and 3 have been solved by single-crystal diffraction. Compound 2 crystallizes as methanol solvate (1:1) in the monoclinic space group P21/n with a = 25.374 (13) Å, b = 11.351 (8) Å, c = 9.338 (5) Å, β = 92.03 (4)°, and Z = 4. Compound 3 crystallizes as toluene solvate (2:1) in the monoclinic space group P21/a with a = 18.090 (10) Å, b = 9.376 (4) Å, c = 17.297 (7) Å, β = 91.76 (4)°, and Z = 4. Both compounds contain a strong intramolecular hydrogen bond which involves the oxygen atom of the benzamidate anion and the cis amine group of the chelate amino-amidine ligand in 2, the free and coordinate ends of the monocoordinate amino-amidine ligand, so forming a pseudo-seven-membered ring, in
Nucleophilic Attack of Amine and Hydroxide to Platinum Dibenzonitrile Dichloride. Crystal structure of [Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl(NHCOPh)] (2) and cis-[Pt(NH=CPhN-t-BuCH2CH2NH-t-Bu)Cl2(NCPh)](3)
No full textSynthesis, Characterization and Olefin/CO Exchange Reactions of Pyrazolylborato Complexes of Copper(I)
No full textNew bis(pyrazolyl)borato olefin complexes of copper(I) of general formula Cu[BH2(3,5-(CF3)2Pz)2]-
(olefin) have been prepared (olefins: coe = cyclooctene, van = 4-vinylanisole, clsty = 4-chlorostyrene,
tevs = triethylvinylsilane, fn = fumaronitrile). The structures of Cu[BH2(3,5-(CF3)2Pz)2](L), L = coe,
van, tevs, fn, have been determined by X-ray diffraction methods. Considering the two N atoms of the
bis(pyrazolyl)borate ligand and the midpoint of the C–C double bond of the coordinated olefin, the
compounds with L = coe, van and tevs contain a copper atom in a trigonal planar coordination. A
coordination polymer with N-coordinated fumaronitrile and tetrahedral coordination of copper atoms
is obtained in the case of L = fn. The carbonylation reactions of Cu[BH2(3,5-(CF3)2Pz)2](olefin)
(olefin = coe, clsty, van, tevs), Cu[BH2(3,5-(CF3)2Pz)2](olefin) + CO↔Cu[BH2(3,5-(CF3)2Pz)2](CO)
+ olefin, have been studied gas volumetrically and the thermodynamical parameters of the equilibria
for the displacement of the coordinated olefin by carbon monoxide have been determined. These data
for copper(I) are compared with those reported in the literature
Carbonyl clusters with a capping methylidyne phosphonate ligand crystal structure of [CO3(CO)9{η1-μ3-[CP(O) (OEt)2]}]
No full textThe bridging methylidyne clusters [Co-3(CO)(9)(eta(1)-mu(3)-[CP(O)(OR)(2)])] 1 (R = Et) and 3 (R = SiMe3) with alpha-phosphoryl substituents have been synthesized by reaction of Cl3C-P(O)(OR)(2) with Co-2(CO)(8), followed by protonation. Cluster 3 was also obtained by the reaction of 1 with Me3SiBr. The structure of 1 has been determined by X-ray crystallography. The donor properties of the P=O function toward Lewis acids such as [Cp2MCl](+) (M = Ti, Zr) were used to assemble early-late metal systems. (C) 1997 Elsevier Science S.A
Nucleophilic substitution on a Ru-coordinated Cp ring by a carborane anion
No full textThe Cp ring in [RuCl(Cp)(PPh3)(2)] undergoes an apparent nucleophilic attack by the carbanion carb (Hcarb = 2-Me-1,2-dicarba-closo-dodecaborane), to give an H-/carb(-) exchange process, which is favoured by coordination of the hydride to the ruthenium centre
Synthesis and crystal structure of (η-C5H5)NiRu3(CO)6(C6H9). A new complex obtained by insertion of a nickel atom into a Ru3 cluster
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