Mono- and dinuclear palladium complexes containing 2-pyridylphosphine ligands, including X-ray characterization of Pd2I2(µ-PPh2py)2 and a dimethylacetylenedicarboxylate A-frame complex Pd2Cl2(µ-Ppy3)2(µ-MeO2C•C=C•CO2Me); py = 2-pyridyl

1992 ◽  
Vol 70 (3) ◽  
pp. 751-762 ◽  
Author(s):  
Yun Xie ◽  
Chung-Li Lee ◽  
Yeping Yang ◽  
Steven J. Rettig ◽  
Brian R. James

Dibromo- and diiodo[(2-pyridyl)phosphine]palladium(II) complexes are prepared by metathesis of cis-PdCl2(PPh3−npyn)2 species (n = 1–3) using the appropriate sodium halide; py = 2-pyridyl. NMR spectroscopy, particularly,13C{1H}, is used to distinguish cis and trans isomers. The dinuclear complexes Pd2X2(μ-PPh3−npyn)2, X = halide, are synthesized via a conproportionation reaction using PdX2(PPh3−npyn)2 and Pd2(dba)3; dba = dibenzylideneacetone. Both Pd2l2(μ-PPh2py)2 and a dimethylacetylenedicarboxylate A-frame complex Pd2Cl2(μ-Ppy3)2(μ-MeO2C•C=C•CO2Me) are characterized crystallographically as head-to-tail isomers. The former crystallizes in the monoclinic space group C2/c with a = 30.992(3), b = 18.764(1), c = 13.100(1) Å, β = 100.676(5)°, and Z = 8; the data were refined to R = 0.035 for 5874 reflections with I ≥ 3σ(I). The A-frame compound is triclinic of space group [Formula: see text] with a = 13.545(2), b = 15.064(2), c = 11.991(2) Å, α = 111.56(1), β = 95.36(1), γ = 97.63(1)°, and Z = 2; R = 0.033 from 7128 reflections with I ≥ 3σ(I). The Pd2X2(μ-PPhpy2)2 complexes exist as a mixture of diastereomers because of chirality induced at the phosphorus atoms. The Pd2X2(μ-Ppy3)2 complexes in water generate the [Pd2(H2O)2(μ-Ppy3)2]2+ dication, which is isolated as various salts. The mononuclear complexes in water generate aquo and hydroxo species. Keywords: dimethylacetylenedicarboxylate adducts, palladium complexes (dinuclear), pyridylphosphines.


Polyhedron ◽  
2000 ◽  
Vol 19 (15) ◽  
pp. 1803-1807 ◽  
Author(s):  
Inamur Rahaman Laskar ◽  
Tapas Kumar Maji ◽  
Siddhartha Chaudhuri ◽  
Ashutosh Ghosh ◽  
Nirmalendu Ray Chaudhuri


2010 ◽  
Vol 14 (11) ◽  
pp. 975-984 ◽  
Author(s):  
Emmanuel Z. Moreira ◽  
Alba D.Q. Ferreira ◽  
Cláudio Roberto Neri ◽  
Sumitra Mukhopadhyay ◽  
Sérgio Dovidauskas ◽  
...  

This work presents the synthesis and characterization of a series of substituted pyridylpentafluroporphyrins, including the separation of the cis- and trans-isomers, the latter being characterized by X-ray crystallography. The spectroscopic and electrochemical properties of the series are dependent on the number of electron withdrawing pentafluorophenyl substituent, but they do not depend on the symmetry of the molecule. Ongoing from the monosubstituted to the more substituted pentafluorophenyl porphyrin H2(MPyTFPP) derivative, the Soret bands are slightly red-shifted and their quantum fluorescence yields range from 0.035 to 0.046, consistent with the value of 0.045 for the fully substituted 5,10,15,20-tetrapentafluorophenylporphyrin (dichloromethane solutions). The redox potentials of the reductive processes of monoanion and dianion formation are also sensitive to the number of pentafluoro substituents, shifting 180 mV to more positive values for the P0/P-1process ongoing from the monopentafluoro to the tris-pentafluorophenyl substituted derivative.



1998 ◽  
Vol 51 (9) ◽  
pp. 807 ◽  
Author(s):  
Andrew M. McDonagh ◽  
Mark G. Humphrey ◽  
David C. R. Hockless

Efficient syntheses of the cis and trans isomers of [OsCl2(Me2SO)4] are reported. While a structural study of thetrans isomer confirms the spectroscopically assigned all-S-bound Me2SO configuration, a crystallographic determination of the cis isomer reveals a previously unheralded all-S-bound Me2SO geometry, in contrast to the spectroscopically inferred configuration predominant in solution which has one O-bound ligand. Fortrans-[OsCl2(Me2SO)4], crystals are tetragonal, space group I 4/m, with a 9·092(2), c 11·212(3) Å, Z 2, 566 unique reflections (34 parameters), converging at R 0·026 and Rw 0·032. For cis-[OsCl2(Me2SO)4], crystals are triclinic, space group P-1, with a 8·193(2), b 8·941(3), c 13·837(3) Å, α 79·77(2), β 79·91(2), γ 65·03(2)°, Z 2, 4152 unique reflections (173 parameters), converging at R 0·021 and Rw 0·018.



2007 ◽  
pp. 3966 ◽  
Author(s):  
Karel D. Klika ◽  
Henri Kivelä ◽  
Vladimir V. Ovcharenko ◽  
Ville Nieminen ◽  
Reijo Sillanpää ◽  
...  


1999 ◽  
Vol 54 (3) ◽  
pp. 349-356 ◽  
Author(s):  
C. Drewes ◽  
W. Preetz

By electrochemical oxidation of (n-Bu4N)[B6H6(CH3)] in the presence of nitrite ions and of the base DBU in dichloromethane solution cis- and trans-[B6H4(CH3)(NO2)]2- , fac- [B6H3(CH3)(NO2)2]2- and mer-[B6H3(CH3)(NO2)c2]2- are formed. X-ray diffraction analyses have been performed on single crystals of cis-(Ph4As)2[B6H4(CH3O)(NO2)] (1) (monoclinic, space group P21/a, a = 20.063(2), b = 10.858(1), c =21.384(2) Å, β = 105.818(9)°, Z = 4), fac-(Ph4As)2[B6H3(CH3)(NO2)2] ·CH3CN (2) (triclinic, space group P1̄, a = 10.333(3), b = 10.695(3), c = 22.833(6) Å, α = 93.91(3), β = 96.79(3), γ = 104.56(2)°, Z = 2), and mer-(Ph4P)2[B6H3(CH3)(NO2)c2] (3) (triclinic, space group P1̄, a - 10.100(1), b = 10.402(3), c = 22.923(3) Å, α = 96.328(18), β = 89.928(12), γ = 107.963(16)°, Z = 2). The 11B NMR spectra and the vibrational spectra of the methylnitro compounds are discussed and compared with those of the monomethyl- and mononitro-closo-hexaborates.



Author(s):  
Marcin Rojkiewicz ◽  
Piotr Kuś ◽  
Maria Książek ◽  
Joachim Kusz

Cathinones belong to a group of compounds of great interest in the new psychoactive substances (NPS) market. Constant changes to the chemical structure made by the producers of these compounds require a quick reaction from analytical laboratories in ascertaining their characteristics. In this article, three cathinone derivatives were characterized by X-ray crystallography. The investigated compounds were confirmed as: 1-[1-(4-methylphenyl)-1-oxohexan-2-yl]pyrrolidin-1-ium chloride (1, C17H26NO+·Cl−, the hydrochloride of 4-MPHP), 1-(4-methyl-1-oxo-1-phenylpentan-2-yl)pyrrolidin-1-ium chloride (2; C16H24NO+·Cl−, the hydrochloride of α-PiHP) and methyl[1-(4-methylphenyl)-1-oxopentan-2-yl]azanium chloride (3; C13H20NO+·Cl−, the hydrochloride of 4-MPD). All the salts crystallize in a monoclinic space group: 1 and 2 in P21/c, and 3 in P21/n. To the best of our knowledge, this study provides the first detailed and comprehensive crystallographic data on salts 1–3.



2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.



1989 ◽  
Vol 44 (5) ◽  
pp. 553-556 ◽  
Author(s):  
Th. Fetzer ◽  
A. Lentz ◽  
T. Debaerdemaeker

Single crystals of Cu(pz)Br2 and Cu(pz)Cl2 were grown by using gel methods with tetramethoxysilane as the gel-forming reagent. Thermal decomposition is interpreted. Crystal data for the bromo complex: monoclinic, space group C2/m with a = 1239.2(3) pm, b = 685.9(2) pm, c = 390.7(3) pm, β = 96,23(5)°. Crystal data for the chloro-complex: monoclinic, space group C2/m with a = 1197.1(3) pm, b = 684.9(3) pm, c = 370.1(3) pm, β = 95.96(5)°. Crystal structure analyses reveal that CuHal2 molecules are bonded by pyrazine to form linear chains. These chains are cross-linked by bridging halogen atoms.



2009 ◽  
Vol 87 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Dana J Eisler ◽  
Stuart D Robertson ◽  
Tristram Chivers

The reaction of (THT)AuCl with (TMEDA)Na[N(TePR2)2] (R = Ph, i-Pr, t-Bu) produces a series of gold (III) complexes of the type [{R2PNP(Te)R2}Au(µ-Te)]2 (4a, R = i-Pr; 4b, R = Ph; 4c, R = t-Bu) rather than the expected homoleptic Au(I) complexes of the ditelluridoimidodiphosphinate ligands. A combination of solution- and solid-state NMR studies shows that both cis and trans isomers of 4a–4c are formed in these reactions. X-ray structural determinations of the trans isomers of 4a–4c reveal a centrosymmetric arrangement with a central four-membered Au2Te2 ring formed by the formal insertion of gold into a P–Te bond; this insertion process was shown to be reversible upon addition of PPh3 to 4a to give the monomeric gold(I) complex Ph3PAu[N{TeP(i-Pr)2}2]. The X-ray structure of cis-4b is also described.Key words: gold, tellurium, redox, X-ray structures, imidodiphosphinate.



1989 ◽  
Vol 54 (6) ◽  
pp. 1332-1338 ◽  
Author(s):  
Marvin L. Lewbart ◽  
Carl Monder ◽  
Walter J. Boyko ◽  
Carol J. Singer ◽  
F. Iohan


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