1,720,997 research outputs found
Metal Derivatives of Azoles. Part V. Platinum(II) and Palladium(II) Pyrazolates as a New Type of Neutral Bidentate Ligands
No full textA series of pyrazole adducts and pyrazolato derivatives of platinum(II) containing various chelating phosphines as ligands: Characterization, 1H and 31P1H NMR spectra
No full textNew pyrazolato derivatives of platinum(II) are isolated, (LL)Pt(pz)2, A, [LL = Ph2P(CH2)nPPh2 (n = 1, 2, 3, or 4), Ph2PCH2CH2AsPh2, (Ph2AsCH2)2 or cis-Ph2PCHCHPPh2; pzH = pyrazole, 3,5-dimethyl,- 3,5-bis(trifluoromethyl)-, or 3,5-dimethyl-4-nitro-pyrazole] by reaction of (LL)PtCl2 with pyrazole and potassium hydroxide in methanol. By protonation of A with fluoboric acid the corresponding pyrazole adducts, [(LL)Pt(pzH)2][BF4]2, B, are obtained when pzH is 3,5-dimethylpyrazole. The properties of the compounds are discussed on the basis mainly of the NMR evidence; 31P data are related to the dimension of the PtP(C)nP ring (n = 1-4) and to the trans-influence of the pyrazolato and pyrazole ligand. © 1982
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
AN IR-193 AND AU-197 MOSSBAUER INVESTIGATION OF IRIDIUM(I), IRIDIUM(III) AND IRIDIUM(I) GOLD(I) COMPLEXES
No full textComparison of the Ir-193 and Au-197 Mossbauer spectra of the series trans-(Ph3P)2Ir(CO)X, trans,cis-(Ph3P)2(H)2Ir(CO)(X) (X = Cl or pz-N; pzH = 3,5-dimethyl-, 3,5-dimethyl-4-nitro-, 3,5-bis(trifluoromethyl)pyrazole) and trans-(Ph3P)2(CO)Ir[mu-(3,5-dimethylpyrazolato-N,N')]AuX' (X' = Cl, Br) shows that even the substituents on the heterocycle influence the electron density at the iridium nucleus and that the bridging pyrazolato ligand transmits electronic effects from gold to iridium through three bonds. The Mossbauer parameters are sensitive to the ligand X but not to the presence of conformers
An Investigation on Various Bis (N-substituted-imino)(alkoxy)methyl platinum(II) Derivatives as Ligands Towards Group IIB Halides and Rhodium Dicarbonyl Chloride
No full textThe adducts A.ZaBr2, B.2nBr2, A.CdI2, A.CdBr2, C.CdI2, B.CdI2, C.HgCI2, C.2HgCl2, D.HgCI2, A.Rh(CO)2Cl were prepared from the corresponding halide and the ligand A, (Ph3P)(ArNC)Pt-[c(OMe)=NAr]2 B, (DFE)Pt{c(OMe)=NAr]2, C, (DPE)Pt-[c(OMe)=NMe]2or D, (DPE)Pt-|c(OMe)=NCgH112(Ar= p-tolyl, DPE= 1,2-bis(diphenylphosphino) ethane). These platinum(II) bidentate ligands are basic since they can be proton at ed at the two imino nitrogens, which are likely to be the donor sites in the adducts
SOME GOLD(III) DERIVATIVES OF PYRAZOLES
No full textVarious gold(III) derivatives of pyrazoles, pzH, were obtained and characterized. Besides the salt [3,5-Ph2pzH2][AuCl4], they included adducts, AuCl3·pzH, μ-pyrazolato-N,N′-derivatives, [Cl2Au(pz)]n (such as: n = 2 and pz = 3,5-diphenyl-4-chloropyrazolato), and one derivative containing both a neutral pyrazole and a pyrazolato ligand, Cl2Au(3,5-Ph2pz-N)(3,5-Ph2pzH)
Reactions of (tertiary phosphine)gold(I) substituted imidazoles or pyrazolones with acidic reagents: protonation, azole displacement, and adduct formation. Crystal structure determination of the adduct 1-methyl-2-(cyclohexylphosphinegoldthiolato)imidazole.2benzimidazole
No full text- …
