Coordination of 6-Methyl-2,2'-bipyridine. Structure of Bivalent Copper and Palladium Complexes

1991 ◽  
Vol 44 (2) ◽  
pp. 219 ◽  
Author(s):  
D Onggo ◽  
DC Craig ◽  
AD Rae ◽  
HA Goodwin

Bis ( ligand ) complexes of 6-methyl-2,2′-bipyridine (L) with copper(II) and palladium(II) have been prepared, and their structures have been determined by single-crystal X-ray diffractometry . In the formation of the complex fromcopper(II) tetrafluoroborate and L, partial hydrolysis of a coordinated fluoroborate ion to the hydroxytrifluoroborate ion occurs. The stereochemistry about copper in [CuL2OHBF3][BF4] is essentially trigonal bipyramidal with an axial compression. The nitrogens of the methyl-substituted pyridine rings coordinate in the axial sites. In [PdL2Cl][BF4] the coordination environment about palladium is square planar and one of the 6-methylbipyridine molecules functions as a unidentate group, the nitrogen of the methyl-substituted pyridine ring being uncoordinated. The average metal-nitrogen distance is 2.032 Ǻ in the copper complex and 2.042 Ǻ in the palladium complex. [CuL2OHBF3][BF4] is monoclinic, space group P21/c, Z = 4, a 9.005(2), b 17.868(2), c 15.298(3) Ǻ, β 104.13(1)°. [PdL2Cl][BF4] is monoclinic, space group P21/c, Z = 4, a 9.606(5), b 14.748(2), c 16.311(8)Ǻ, β 96.13(2)°.


1985 ◽  
Vol 40 (2) ◽  
pp. 251-257 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Bernt Krebs

Abstract The compounds [(C6H5)4As]2 TeCl4 (1), [(C2H5)4 N]2 TeBr4 · CH3CN (2), and [(C2H5)4N]2TeI4 (3) were prepared by the reaction of Te, X2 , and excess (C2H5)4NX (X = Br, I) in acetonitrile solution or by heating of [(C6H5)4 As]2TeCl6 , Te, and (C6H5)4 ASCl for several hours in the same solvent.The structures of 1-3 were determined from single crystal X-ray data.1 crystallizes in the monoclinic space group P21/n with a = 1061.8(2), b = 1614.2(3), c = 1341.7(3) pm, β = 94.21° and Z = 2; 2: tetragonal, P4/mmm, a = 1039.7(2), c = 690.5(1), Z = 1; 3: tetragonal, I4/mmm, a = 1061.7(2), c = 1342.8(4), Z = 2. In 1-3 Te(II) exhibits a square planar coordination. The Te -CI, Te -Br, and Te-I bond lengths were found to be 260.7 (mean), 275.3, and 298.5 pm, respectively.



1994 ◽  
Vol 47 (7) ◽  
pp. 1223 ◽  
Author(s):  
JE Cosgriff ◽  
GB Deacon ◽  
BM Gatehouse ◽  
H Hemling ◽  
H Schumann

The complexes Ln (But2pz)3( thf )2 ( Ln = Y, La, Pr, Nd , Sm, Gd, Dy , Er , Yb, Lu; But2pz- = 3,5-di-t-butylpyrazolate; thf = tetrahydrofuran ), and [ Ln (But2pz)3(OPPh3)2].( dme )n ( Ln = La, n = ⅔ ; Ln = Er , n = 1; dme = 1,2-dimethoxyethane) have been prepared by reaction of the lanthanoid metal with bis ( pentafluorophenyl )mercury and the corresponding pyrazole in either thf , or in dme in the presence of triphenylphosphine oxide. The X-ray crystal structure of Er (η2-But2pz)3( thf )2 [monoclinic, space group P21 (No. 4), a 9.738(4), b 19.602(4), c 11.636(4) Ǻ, β 99.42(3)°, R 0.0374 for 3667 observed reflections] shows the complex to be an eight-coordinate monomer with three chelating But2pz ligands . The arrangement of centres ( Cen ) of the N-N bonds of the But2pz ligands [< Er -N> 2.336 Ǻ; Cen-Er-Cen 140.1(4)°, 110.3(4)° and 109.6(4)°] and the thf oxygen atoms [< Er -O> 2.351 Ǻ; O- Er -O 140.1(4)°] is intermediate between trigonal bipyramidal and square pyramidal. The other Ln (But2pz)3( thf )2 complexes and Ln (But2pz)3(OPPh3)2 are considered to have similar structures.



1983 ◽  
Vol 36 (1) ◽  
pp. 183 ◽  
Author(s):  
EJ O'Reilly ◽  
G Smith ◽  
CHL Kennard ◽  
AH White

The crystal structures of two copper(II) complexes of the herbicide Picloram (4-amino-3,5,6-trichloro- pyridine-2-carboxylic acid) have been determined by single-crystal X-ray diffractometry. Bis(4-amino- 3,5,6-trichloropyridine-2-carboxylato)aquacopper(II) dihydrate (1) is monoclinic, space group C2/c, with Z 4 in a cell of dimensions a 15.593(6), b 7.940(6), c 16.983(6) �, β 107.58(3)�. The structure was refined to a residual R 0.046 for 905 'observed' reflections. Complex (1) is trigonal bipyramidal with the trigonal plane consisting of oxygens from two picolinate ligands [Cu-O 1.995(5) �] and a water molecule [Cu-O 2.080(5) �]. The apical positions are occupied by pyridine ring nitrogens from the Picloram ligands [Cu-N 2.021(5) �]. Bis(4-amino-3,5,6-trichloropyridine- 2-carboxylato)bis(pyrimidin-2-amine)copper(II) (2) is monoclinic, space group P2,/c, with Z 4 in a cell of dimensions a 12.3 11(5), b 15.435(5), c 15.320(6) �, β 115.95(3)�, and gave a final R 0.059 for 2429 'observed' reflections. In complex (2), the copper(II) atom has a tetragonally distorted octahedral stereochemistry with the Picloram ring nitrogens once again occupying the two axial positions [Cu-N 2.586(7) and 2.611(7) �]. The square plane consists of two carboxylato oxygens [Cu-O 1.941(6) and 1.960(7) �] and two hetero-nitrogens from pyrimidin-2-amine ligands [Cu-N 2.048(6) and 2.054(6) �].



1983 ◽  
Vol 38 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Bernt Krebs ◽  
Marita Hucke ◽  
Michael Hein ◽  
Andreas Schäffer

Abstract The monomeric SeOCl3- ion, which can be prepared as the tetraphenylarsonium salt from SeOCl2 and As(C6H5)4Cl, was structurally characterized by a low-temperature single crystal X-ray diffraction analysis. [As(C6H5)4]SeOCl3 is monoclinic, space group P21/c, with a = 9,332(3), b = 13,761(4), c = 18,985(6) Å, β = 110,97(3)° (at -135 °C), Z = 4; it contains a novel type of ψ-trigonal bipyramidal oxotrichloroselenate(IV) anion which is not associated to dimers or polymer chains as in known structures. The equatorial positions are occupied by doubly bonded oxygen (Se-O 1,601(3) Å) and by one Cl(Se-Cl 2,234(1) Å), the axial Se-Cl bonds (2,430(1) and 2,475(1) Å) being significantly longer. [N(C2H5)4]SeOCl3, which was obtained as crystals by oxidation of trichloroselenate(II), is triclinic, space group P1̄, with a = 10,607(3), b = 8,950(2), c = 8,862(2) Å, α = 119,79(2)°, β = 101,07(2)°, γ = 96,28(2)°, Z = 2. The X-ray structure analysis shows the anions to be present as centrosymmetric dimers Se2O2Cl62- like in the [P(C6H5)4]+ salt, with two tetragonal SeOCl4 pyramids linked through a Cl···Cl edge and the lone pairs trans to the axial Se-O bonds (1,589(4) Å). Se-Cl bond lengths are 2.270(1) and 2,351(2) Å (terminal); 2,698(1) and 2,920(1) Å (bridging). The results show that the nature of the reaction products of the Lewis acid SeOCl2 with halogenides as bases changes very sensitively with small variations in cations and environment. The vibrational spectra are discussed.



2006 ◽  
Vol 84 (7) ◽  
pp. 971-978 ◽  
Author(s):  
Soria Meghdadi ◽  
Mehdi Amirnasr ◽  
Vratislav Langer ◽  
Alison Zamanpoor

Cobalt(II), nickel(II), copper(II), and two cobalt(III) complexes of a new dianionic ligand, bqb, [H2bqb = N,N'-bis(2-quinolinecarboxamide)-1,2-benzene] have been synthesized and characterized by elemental analyses, IR, and 1H NMR spectroscopy. The crystal and molecular structures of the [Ni(bqb)] (2) and [N(n-Bu)4][CoIII(bqb)(N3)2] (5) complexes were determined by X-ray crystallography. Complex 2 crystallizes in the monoclinic space group C2/c with a distorted square-planar structure including two short Ni–N (1.848 Å) and two long Ni–N (1.958 Å) bonds. The structure consists of sheets formed in the plane parallel to the b axis and diagonal to vectors a and c by intermolecular hydrogen bonds. Complex 5 crystallizes in the monoclinic space group C2 with a distorted octahedral structure. The [N(n-Bu)4]+ ion is disordered at the C3A and C4A atoms of one Bu. The IR and 1H NMR spectra of the complexes are also discussed.Key words: N4-dianionic amido ligand (bqb), (bqb) complexes of Co(II), Ni(II), Cu(II), and Co(III), azide, cyanide, X-ray crystal structures.



1995 ◽  
Vol 73 (2) ◽  
pp. 255-263 ◽  
Author(s):  
Bozena Borecka ◽  
T. Stanley Cameron ◽  
M. Azad Malik ◽  
Barry C. Smith

Aryltellurium(IV) trichlorides react with 3-cyclohexene-1-methanol and 3-cyclohexene-1,1-dimethanol to give aryl(trans-6-oxabicyclo[3.2.1]oct-4-yl)tellurium(IV) dichlorides and aryl(cis-1-hydroxymethyl-trans-6-oxabicyclo[3.2.1]oct-4-yl)tellurium(IV) dichlorides. The structure of 2′,4′-dimethoxyphenyl(trans-6-oxabicyclo[3.2.1]oct-4-yl)tellurium(IV) dichloride has been determined by single crystal X-ray analysis. The compound C15H20Cl2O3Te, Mr = 446.8, crystallizes in the monoclinic space group P21/c with a = 9.626(2) Å, b = 15.768(5) Å, c = 11.176(3) Å, β = 92.08(1)°, V = 1695.2(5) Å3 and D(calc) = 1.751 for Z = 4. Tellurium is bonded axially to two chlorines and equatorially to aryl carbon and carbon from the cyclohexyl portion of oxabicyclo[3.2.1]oct-4-yl in a pseudo-trigonal-bipyramidal arrangement having an equatorial lone pair of electrons. Bond lengths are Te—Cl(1) = 2.492(3) Å, Te—Cl(2) = 2.539(3) Å, Te—C(4) = 2.175(10) Å, and Te—C(9) = 2.090(10) Å. Keywords: organotellurium(IV), 3-cyclohexene-1-methanol, 3-cyclohexene-1, 1-dimethanol.



1993 ◽  
Vol 46 (12) ◽  
pp. 1881 ◽  
Author(s):  
JE Cosgriff ◽  
GB Deacon ◽  
BM Gatehouse

From reaction of lanthanoid metals with bis ( pentafluorophenyl )mercury and 3,5-diphenylpyrazole (HPh2pz) in 1,2-dimethoxyethane ( dme ) and treatment of the products with triphenylphosphine oxide, the complexes [ Ln (η2-Ph2pz)3(OPPh3)2].( dme )n ( Ln = Er or Nd , n = 1; Ln = La, n = 0.6) have been isolated. An X-ray crystal structure shows that the erbium complex [monoclinic, space group C2, a 22.08(3), b 14.30(1), c 13.37(1) Ǻ, β 124.09(7)°, Z 2 2730 'observed' data refined to R 0.046] is monomeric , with eight coordination of the metal. There is a trigonal bipyramidal arrangement of the centre ( Cen ) of the N-N bonds of three η2-3,5-diphenylpyrazolate groups ( ΣCen-Er-Cen 360°; ( Er -N) 2.344 Ǻ) and the oxygens of two equivalent trans triphenylphosphine oxide ligands [O- Er -O 176(1)°; Er -O 2.207(9)Ǻ]. Unit cell data indicate that the neodymium analogue [monoclinic, space group C2, a 23.01(3), b 14.94(2), c 13.82(2) Ǻ, β 123.65(8)°] is isostructural with the erbium complex. An analogous reaction of lanthanum or neodymium metal, Hg(C6F5)2, and HPh2pz in tetrahydrofuran ( thf ) gives [ Ln (η2-Ph2pz)3( thf )3]. thf ( Ln = La or Nd ). The X-ray crystal structure of the neodymium complex [orthorhombic, space group P212121, a 14.009(9), b 16.280(8), c 22.640(16)Ǻ, Z 4, 2967 'observed' data refined to R 0.046 reveals a nine-coordinate monomer with three η2-Ph2pz ligands [ Nd -N 2.420(10)-2.524(8)Ǻ] and three thf ligands [ Nd -O 2.497(8)-2.587(8)Ǻ]. There is a trigonal prismatic arrangement of the centres of the N-N bonds and the oxygen donor atoms.



1993 ◽  
Vol 71 (3) ◽  
pp. 358-363 ◽  
Author(s):  
Juan N. Fernández-G. ◽  
Raúl G. Enríquez ◽  
Amalia Tobón-Cervantes ◽  
Margarita I. Bernal-Uruchurtu ◽  
René Villena-I ◽  
...  

The crystal structures of N,N′-di(2-acetylcyclohexenyl)ethylenediamine (L1) and its copper(II) complex, which crystallizes with one solvent molecule of chloroform (Cu(L1-2H)•CHCl3), were determined. Crystallographic details are as follows: L1 is monoclinic, space group P21/c, with a = 8.280(2), b = 11.692(2), and c = 9.355(2) Å, β = 114.10(2)°, V = 826.7(3) Å3, Z = 2; ρc = 1.22 g cm−3, μ(Cu Kα) = 5.93 cm−1, with the final residual indices of R = 0.046 and Rw = 0.070 for 991 unique reflections. Cu(L1-2H)•CHCl3 is triclinic, space group[Formula: see text] with a = 11.121(3), b = 11.713(3), and c = 8.974(2) Å, α = 99.35(2)°, β = 110.83(2)°, γ = 82.33(2)°, V = 1074(1) Å3, Z = 2; ρc = 1.50 g cm−3, μ(Cu Kα) = 50.74 cm−1, with the final residual indices of R = 0.048 and Rw = 0.077 for 2369 unique reflections. The X-ray diffraction study shows that in the crystal state the ligand L1 is in the methylketonecyclohexanonenamine isomeric form. For the copper complex Cu(L1 2H)•CHC13, the geometry around the metal atom is distorted square planar, and the angle between the chelate ring planes in the complex is 15.1°. An NMR study shows that L1 in solution has the same structure as that observed in the solid state by X-ray diffraction.



1988 ◽  
Vol 43 (3) ◽  
pp. 253-256 ◽  
Author(s):  
Franz A. Mautner ◽  
Harald Krischner ◽  
Christoph Kratky

Zinc azide · 4-methylpyridine (1) is formed by the reaction of zinc azide with the corresponding pyridine in aqueous solution. The crystal structure was determined by single crystal X-ray diffraction methods. The crystals of 1 are monoclinic, space group C2/c, Z = 4, a = 1085.5(2), b = 1692.7(11), c = 619.7(6) pm, β = 113.47(5)°. Each zinc atom is surrounded by five nitrogen atoms (four from azide groups and one from the pyridine adduct) in a distorted trigonal bipyramidal fashion. The ZnN5-polyhedra share common edges to form chains along the crystallographic c-axis.



1986 ◽  
Vol 64 (2) ◽  
pp. 343-352 ◽  
Author(s):  
David Eric Berry ◽  
Kathryn Anne Beveridge ◽  
Gordon William Bushnell ◽  
Keith Roger Dixon ◽  
Alan Pidcock

Hydrolysis of cis-[PtCl2-{P(OEt)2Cl}2] results in condensation of the phosphite to form [Pt2Cl4{μ-(EtO)2POP(OEt)2}2], which crystallizes in the monoclinic space group P21/n, with a = 13.814(7), b = 11.429(4), c = 10.726(5) Å, β = 106.30(5)°. Reactions of P(OEt)2Cl or (EtO)2POP(OEt)2 with [Pt2Cl4(PEt3)2] also yield very easily hydrolyzed products but in these cases an even more complex condensation occurs to yield [Cl2Pt{(μ-(P(OEt)2O)2P(O)}PtCl(PEt3)2], which crystallizes in the monoclinic space group P21/c, a = 17.547(8), b = 19.775(6), c = 11.268(3) Å, β = 106.42(3)°. Complete X-ray diffraction studies are reported for both crystals, confirming the presence of double (EtO)2POP(OEt)2 bridges in [Pt2Cl4{(μ-(EtO)2POP(OEt)2}2] and a novel triphosphite bridge in [Cl2Pt{μ-(P(OEt)2O)2P(O)}PtCl(PEt3)2]. Detailed analyses and computer simulation of the 31P{1H} and 195Pt{1H} nmr spectra of these complexes are also described, together with studies of the related compounds, [Pt2Me4{μ-(EtO)2POP(OEt)2}2] and [Cl2(Et3P)Pt{μ-(EtO)2POP(OEt)2}PtCl2(PEt3)]. In conjunction with previous studies of [Pt2Cl2(dppm)2] and related complexes, these spectra provide examples of several types of AA′XX′ spin systems and the analysis of these systems is discussed in detail.



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