Organomercury Compounds. XXXI. Preparations and 199Hg N.M.R. Spectra of Organomercury Derivatives of 2-Phenylpyridine, Benzo[h]quinoline, 1-Phenylpyrazole and 3,4,5-Trimethyl-1-phenylpyrazole, and the X-Ray Crystal Structure of Bis[2-(pyridin-2'-yl)phenyl]mercury

1993 ◽  
Vol 46 (9) ◽  
pp. 1323 ◽  
Author(s):  
DS Black ◽  
GB Deacon ◽  
GL Edwards ◽  
BM Gatehouse

2-(Pyridin-2'-yl) phenylmercuric acetate has been prepared by mercuration of 2-phenylpyridine. Symmetrization of the corresponding chloride by alkaline sodium stannite gave bis [2-(pyridin-2'-yl)phenyl]mercury, which was also prepared from 2-(2'-aminophenyl)pyridine by the diazo method and treatment of the initial product with copper powder and aqueous ammonia. Mercuration of benzo [h] quinoline and 3,4,5-trimethyl-1-phenylpyrazole with mercuric acetate followed by treatment with lithium chloride yielded benzo [h]quinolin-10-ylmercuric chloride and 2-(3',4',5'-trimethylpyrazol-1'-yl) phenylmercuric chloride respectively. Treatment of the former product with tribromide ions gave 10-bromobenzo[h] quinoline. The exchange Grignard reaction between 1-phenylpyrazole and ethylmagnesium bromide to give 2-(pyrazol-1'-yl) phenylmagnesium bromide has been monitored by reactions with benzonitrile and D2O to establish optimum conditions for reaction with mercuric bromide giving bis [2-(pyrazol-1'-yl)phenyl]mercury. The 199Hg n.m.r. chemical shifts of the majority of mercurials are shifted substantially downfield relative to the corresponding simple phenylmercurials consistent with weak intramolecular coordination by the heterocyclic nitrogen donor atoms, but a small upfield shift is observed for bis [2-(pyrazol-1'-yl)phenyl]mercury. The X-ray crystal structure of bis [2-(pyridin-2′-yl)phenyl]mercury [monoclinic, space group P21/n, a 12.746(2), b 11.660(2), c 5.698(1) Ǻ, β 92.81(1)′, V 845.8 Ǻ3] shows a centrosymmetric molecule with strong linear two coordination [Hg-C 2.098(8) Ǻ; C-Hg-C 180.0°] and significant but much weaker Hg-N interactions [Hg-N 2.798(7) Ǻ; N-Hg-N 180.0°] giving overall distorted square planar stereochemistry. The phenyl rings are mutually coplanar, whilst the two pyridin-2'-yl rings are parallel and inclined at 10.8° to the phenyl groups.

1995 ◽  
Vol 73 (9) ◽  
pp. 1520-1525
Author(s):  
Luciano Antolini ◽  
Ugo Folli ◽  
Dario Iarossi ◽  
Adele Mucci ◽  
Silvia Sbardellati ◽  
...  

The crystal structures of the title compounds were determined by single crystal X-ray diffraction techniques. The molecule of the Z isomer, which crystallizes in the monoclinic space group C2/c with Z = 4 in a cell of dimensions a = 14.891 (2), b = 10.780(2), c = 8.769(1) Å, β = 97.47(2)°, V = 1395.7(7) Å3 has crystallographic twofold symmetry. The E form crystallizes in the orthorhombic space group Pbca with a = 11.730(1), b = 6.932(1), c = 16.841(1) Å, V = 1369.4(2) Å3 and Z = 4. Its molecules have crystallographically dictated [Formula: see text] symmetry. In both isomers the phenyl rings are roughly perpendicular to the average ethylene plane. The atoms characterizing this plane show significant deviations from planarity in the Z isomer. Marked bond-angle distortions at the ethene carbons of both structures are observed. The 1H and 13C NMR spectra of the compounds were measured and, particularly in the case of the 1H chemical shifts, fall into two quite separate spectral regions. At low temperature, two conformational isomers, those with different relative orientation of the C—Cl bonds of the phenyl rings, are observed in the spectrum of each compound. Keywords: chlorostilbenes, overcrowded molecules. X-ray structure, conformations, NMR spectroscopy.


2006 ◽  
Vol 61 (2) ◽  
pp. 153-158
Author(s):  
Okan Zafer Yeşilel ◽  
Halis Ölmez ◽  
Hümeyra Paşaoğlu ◽  
Gökhan Kaştaş ◽  
Orhan Büyükgüngör

AbstractBis(2-aminopyrimidine-N)diaquabis(saccharinato-O)copper(II) di(2-aminopyrimidine), [Cu(sac-O)2(ampym-N)2(H2O)2] · 2ampym was synthesized and characterized by means of elemental analysis, IR and UV-vis spectroscopy, magnetic susceptibility, simultaneous TG, DTG, DTA techniques, and X-ray diffraction. The complex crystallizes in the monoclinic space group P21/c [a = 7.4697(5), b = 10.1679(5), c = 22.743(2)Å , β = 92.844(5), Z = 2, R = 0.0275, wR= 0.0757, V = 1725.26(19) Å3]. The copper atom is bonded to two ampym N atoms and two sac O atoms as well as to two water O atoms in trans positions in the geometry of a distorted octahedron. There are also two ampym moieties as solvate molecules in the unit cell. The crystal structure is stabilized by N-H· · ·O, O-H· · ·N and C-H· · ·O type hydrogen bonding interactions. Intermolecular π−π interactions between the phenyl rings of ampym groups and C-H· · ·π interactions also support the packing of the molecules. The thermal decomposition of the complex has been studied.


1984 ◽  
Vol 62 (12) ◽  
pp. 2657-2660 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson

Three types of complexes, trans-[Pt(LH)2Cl2], [Pt(L)2], and [Pt(LH)2(SR)2] where LH = NH2—C(CH3)2(CH2OH) and NH2—C(CH2OH)3 and L are the deprotonated ligands, have been synthesized.The crystal structure of trans-[Pt(NH2—C(CH3)2CH2OH)2Cl2] has been determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with a = 6,282(3), b = 20,901(13), c = 10,769(10) Å, β = 92,64(6)°, and Z = 4. The structure was refined by full-matrix least-squares analysis to a conventional R factor of 0.049 and Rw = 0.042. The coordination around the platinum atom is square planar. The Pt—Cl distances are 2.306(2) and 2.309(3) Å and the Pt—N bonds are 2.060(8) and 2.071 (7) Å. The hydroxyl oxygen atoms are disordered; the disorder is different for each organic ligand. The structure is stabilized by an extensive hydrogen bonding system.


1989 ◽  
Vol 67 (1) ◽  
pp. 48-53 ◽  
Author(s):  
David Eric Berry ◽  
Jane Browning ◽  
Gordon William Bushnell ◽  
Keith Roger Dixon ◽  
Alan Pidcock

Reaction of "cyclamphosphorane" (cyclamPH) with [Pt2Cl4(PEt3)2] yields [PtCl(PEt3)(cyclamPH)]Cl. The complex crystallizes as a dichloromethane solvate in the monoclinic space group P21/n, with a = 13.877(3), b = 23.231(7), c = 8.295(2)Å, β = 91.86(4)°, and an X-ray diffraction study shows square planar platinum coordination in which the labile proton of cyclamPH has transferred from phosphorus to nitrogen and the ligand is attached via simple [Formula: see text] chelation. The phosphorus is trans to chlorine in the platinum coordination plane.The corresponding product, trans-[PtCl2(PEt3)(cyclenPH2)]Cl, derived from reaction of "cyclenphosphorane" (cyclenPH) with [Pt2Cl4(PEt3)2], is shown by NMR studies to have a quite different structure in which the ligand is protonated at two nitrogen sites but not at phosphorus. The phosphorus is pentacoordinate with four attachments to nitrogen atoms and one to platinum. The two chlorine atoms are mutually trans in the platinum coordination plane. Keywords: crystal structure, cyclenphosphorane reaction, cyclamphosphorane reaction, X-ray diffraction.


1977 ◽  
Vol 55 (17) ◽  
pp. 3111-3117 ◽  
Author(s):  
Mlchał Sabat ◽  
Tadeusz Głowiak ◽  
Jerzy Szychowski ◽  
Jerzy T. Wrôbel ◽  
Andrzej Leniewski

Racemic 3-epinupharamine hydrobromide (C15H26BrNO2) crystals are monoclinic, space group C2/c, with a = 18.163(3), b = 13.346(2), c = 13.847(2) Å, β = 100.36(1)°, Z = 8. The X-ray analysis proved the structural identity of the compound obtained by the total synthesis with the natural 3-epinupharamine. The empirical criterion indicating the axial or equatorial orientation of the C-methyl group on the basis of the direction of changes of the chemical shifts recorded in benzene solutions does not hold for the piperidine system investigated.Les cristaux du bromhydrate d'épi-3 nupharamine racémique (C15H26BrNO2) sont monocliniques, groupe d'espace C2/c avec a = 18.163(3), b = 13.346(2), c = 13.847(2) Å, β = 100.36(1)°, Z = 8. L'analyse par rayons-X a démontré l'identité structurale du composé obtenu par synthèse totale avec l'épi-3 nupharamine naturel. Les critères empiriques permettant de déterminer l'orientation axiale ou équatoriale des groupes C-méthyles en se basant sur la direction des changements dans les déplacements chimiques enregistrés en solutions benzéniques ne peuvent être utilisés dans le système pipéridine étudié. [Traduit par le journal]


1989 ◽  
Vol 44 (12) ◽  
pp. 1483-1487 ◽  
Author(s):  
Hans Georg Stammler ◽  
Johannes Weiss

(S4N3)2Se2Cl10, (S4N3)2Se2Cl6 and [(S4N3)SeCl5]n are formed by the reaction of S4N4, Se2Cl2, and SOCl2. The structures of the three compounds where determined by X-ray diffraction. The yellow crystals of (S4N3)2Se2Cl,10 are monoclinic, space group P21/a, a = 817.5(2) pm, b = 1790.4(5) pm, c = 843.1(6) pm, β = 104.31(4)°, Z = 2. The Se2Cl,102- anion consists of 2 Cl-bridged distorted octahedra. (S4N3)2Se2Cl6 forms red monoclinic crystals, space group P21/c, a = 1036.5(3) pm, b = 1376.5(5) pm, c = 1400.4(4) pm, β = 100.65(2)°, Ζ = 4. In the Se2Cl62- anion the Se atoms have a square planar environment. The yellow crystals of (S4N3)SeCl5 are orthorhombic, space group P212121, a = 734.2(3) pm, b = 989.4(4) pm, c = 1627.4(6) pm, Z = 4. In the SeCl5- anion the Se atom has an octahedral environment of chlorine atoms, thus forming a polymeric structure.


1988 ◽  
Vol 66 (12) ◽  
pp. 3162-3165 ◽  
Author(s):  
Elmer C. Alyea ◽  
George Ferguson ◽  
John Malito ◽  
Barbara L. Ruhl

The bulky trimesitylarsine ligand, As(mes)3, undergoes facile cyclopalladation to yield the dimeric complex, [Formula: see text], characterized by microanalysis, IR and 1H NMR spectroscopy. This complex is very stable but readily undergoes bridge-cleavage reactions with tertiary phosphine ligands having ligand cone angles less than 170°. The crystal structure for the PPh3 bridge-cleavage product is reported. This complex, [Formula: see text] is monoclinic, space group P21/c with a = 20.469(2), b = 12.702(2), c = 15.401(4) Å, β = 98.46(1)°, V = 3961 Å3Z = 4, R = 0.0284 and Rw = 0.0305. The Pd geometry is distorted square-planar with principal dimensions, Pd—Cl 2.395(1), Pd—P 2.318(1), Pd—C 2.056(3), and Pd—As 2.437(1) Å; As—Pd—Cl 96.5(1), Cl—Pd—P 90.9(1), P—Pd—C 93.7(1), As—Pd—C 78.9(1), As—Pd—P 172.6(1), and Cl—Pd—C 171.7(1)°. The average C—P—C angle (104.3(1)°) is smaller than expected and is rationalized on the basis of steric effects operative within the complex.


1989 ◽  
Vol 67 (12) ◽  
pp. 2209-2212 ◽  
Author(s):  
F. D. Rochon ◽  
R. Melanson ◽  
Monique Doyon

Complexes of the type cis-Pt(L)(un)Cl2 where L = primary amine or methyl derivative of pyridine and un = cyclopentene, cyclohexene, or dimethylhexynediol, have been synthesized from the reaction of K[Pt(L)Cl3] with the unsaturated ligand in water. The compounds were characterized and studied by 1H NMR and IR spectroscopy. The crystal structure of cis-Pt(CH3NH2)((CH3)2C(OH)—C≡C—C(OH)(CH3)2)Cl2 was determined by X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with a = 6.544(2), b = 14.304(7), c = 15.508(7) Å, β = 109.39(2)°, and Z = 4. The coordinates and the anisotropic thermal factors were refined by full-matrix least-squares analysis to a R factor of 0.048 and wR = 0.047. The coordination around the platinum atom is square planar and the acetylenic ligand is perpendicular to the Pt plane. Keywords: platinum complexes, crystal structure, methylamine, dimethylhexynediol, synthesis.


Author(s):  
H.-J. Cantow ◽  
H. Hillebrecht ◽  
S. Magonov ◽  
H. W. Rotter ◽  
G. Thiele

From X-ray analysis, the conclusions are drawn from averaged molecular informations. Thus, limitations are caused when analyzing systems whose symmetry is reduced due to interatomic interactions. In contrast, scanning tunneling microscopy (STM) directly images atomic scale surface electron density distribution, with a resolution up to fractions of Angstrom units. The crucial point is the correlation between the electron density distribution and the localization of individual atoms, which is reasonable in many cases. Thus, the use of STM images for crystal structure determination may be permitted. We tried to apply RuCl3 - a layered material with semiconductive properties - for such STM studies. From the X-ray analysis it has been assumed that α-form of this compound crystallizes in the monoclinic space group C2/m (AICI3 type). The chlorine atoms form an almost undistorted cubic closed package while Ru occupies 2/3 of the octahedral holes in every second layer building up a plane hexagon net (graphite net). Idealizing the arrangement of the chlorines a hexagonal symmetry would be expected. X-ray structure determination of isotypic compounds e.g. IrBr3 leads only to averaged positions of the metal atoms as there exist extended stacking faults of the metal layers.


1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2


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