The crystal and molecular structures of the bispyridine and 1,10-phenanthroline adducts of Bis(ethyl 3-mercaptobut-2-enoato)nickel(II)

1982 ◽  
Vol 35 (2) ◽  
pp. 331 ◽  
Author(s):  
J Sachinidis ◽  
MF Mackay ◽  
MW Grant

X-ray analyses of monoclinic crystals of the bispyridine and 1,10-phenanthroline adducts of the monothioacetylacetonate complex bis(ethyl 3-mercaptobut-2-enoato)nickel(n), Ni(eosm)2,* have defined their structures. Crystals of the bispyridine adduct Ni(eosm)2,py2, C22H28N2NiO4S2, belong to the space group P21/c with a 8.865(6), b 15.758(4), c 9.136(3)Ǻ, β 109.18(4)°, Z 2. Crystals of the 1,10-phenanthroline adduct Ni(eosm)2,phen, C24H26N2NiO4S2, belong to the space group P21c with a 12.451(2), b 16.949(1), c 15 5921(2) Ǻ, β 130.97(1)°, Z 4. The structures were refined with diffractometer data measured with Cu Ka radiation to R 0.047 (1962 terms) for the bispyridine adduct and R 0.061 (3115 terms) for the phenanthroline adduct. The geometry about the nickel in each complex is distorted octahedral. The molecule of the bispyridine adduct has exact rn symmetry with the two sulfur atoms cis-equatorial and the nitrogen atoms axial. In the phenan- throline adduct, pairs of sulfur, nitrogen and oxygen atoms are in cis configurations. In the bis-pyridine adduct, the Ni-N bond lengths, 2.153(3) and 2.182(4) Ǻ, are significantly longer than those in other bispyridine adducts of nickel(II) species. It is suggested that the long Ni-N distances reflect the relative instability of the bispyridine adduct, and thermodynamic data are presented to support this.

1992 ◽  
Vol 45 (2) ◽  
pp. 429 ◽  
Author(s):  
AT Baker ◽  
MT Emett

The structures of [Pt(S2CN(C2H5)2)2] (1) and [Pt(S2CN(C2H4OH)2)2] (2) have been determined by single-crystal X-ray diffractometry. Compound (1) crystallizes in the tetragonal space group P42/n, a 16.4692(10),c 6.2160(6) � (Z = 4); R was 0.029 for 1012 observed reflections. Compound (2) is monoclinic, space group Pc, a 6-0663(11), b 1.1784(15), c 12.5740(21) � ,β92.569(8)� (Z = 2); R was 0.019 for 1573 observed reflections. The presence of electron-withdrawing groups in the ligands of (2) appears to have little effect on the Pt-S distances but causes an increase in the C-N bond length, with the C-N bond lengths being significantly different at the 2 σ level.


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) �].


1986 ◽  
Vol 41 (11) ◽  
pp. 1337-1340 ◽  
Author(s):  
Christian Robl ◽  
Armin Weiss

Abstract ZnC6(NO2)2O4 · 2 H2O was grown in aqueous silicagel. It crystallizes monoclinically (space group I2/c). Zn2+ has CN 6 . It is surrounded in a distorted octahedral fashion by 2 water molecules in cis -position and 4 oxygen atoms of the bis-chelating [C6(NO2)2O4]2- ions. Thereby infinite corrugated chains are formed consisting of Zn2+ and the nitranilate dianions. These chains are interlinked by hydrogen bonds between H2O and the NO2 groups. The NO2 groups are twisted against the ring plane. The bond lengths in the dianion are typical of completely delocalized π-electrons.


1988 ◽  
Vol 41 (3) ◽  
pp. 283 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker

The structures of two crystalline modifications of mer -(Pme2Ph)3H-cis-Cl2IrIII, (1), have been determined from single-crystal X-ray diffraction data. Modification (A) is monoclinic, space group P21/c with a 12.635(1), b 30.605(3), c 14.992(2)Ǻ, β 110.01(2)° and Z = 8. Modification (B) is orthorhombic, space group Pbca with a 27.646(3), b 11.366(1), c 17.252(2)Ǻ and Z = 8. The structures were solved by conventional heavy atom techniques and refined by full-matrix least- squares analyses to conventional R values of 0.037 [(A), 8845 independent reflections] and 0.028 [(B), 5291 independent reflections]. Important bond lengths [Ǻ] are Ir -P(trans to Cl ) 2.249(1) av. (A) and 2.234(1) (B), Ir -P(trans to PMe2Ph) 2.339(2) av. (A) and 2.344(1), 2.352(1) (B), Ir-Cl (trans to H) 2.492(2), 2.518(2) (A) and 2.503(1) (B) and Ir-Cl (trans to PMe2Ph)2.452(2) av. (A) and 2.449(1)(B). Differences in chemically equivalent metal- ligand bond lengths emphasize the importance of non-bonded contacts in determining those lengths.


1984 ◽  
Vol 37 (6) ◽  
pp. 1171 ◽  
Author(s):  
DG Allen ◽  
CL Raston ◽  
BW Skelton ◽  
AH White ◽  
SB Wild

The (�)-benzyl(methyl)(4-methylphenyl)(naphthalen-1-yl)arsonium cation has been synthesized and subsequently resolved by fractional crystallization of monohydrogen [R-(R*,R*)]-2,3-bis(benzoyloxy)- butanedioate salts. The separated diastereoisomers were converted into the corresponding optically active arsonium bromides by ion-exchange column chromatography. The absolute configuration of the arsonium cation exhibiting a positive rotation at 589 nm (sodium D line) has been established as (R) by single-crystal X-ray analysis of both the bromide and hexafluorophosphate salts. The arsonium bromide with [α]D + 54.8�(c, 0.62 in CH2Cl2) crystallizes in the orthorhombic space group P212121 (D24, No.19) with a 22.472(8), b 15.724(7), c 12.585(5) � and U 4447(3) �3. The corresponding hexafluorophosphate with [α]D + 19.3� (c, 0.5 in CH2Cl2) crystallizes in the same space group with a 23.56(2), b 16.40(1), c 13.12(1) � and U 5067(6) � 3. Benzylidene transfer to benzaldehyde from the arsonium ylide derived from either of the arsonium salts produced optically pure (–)-(S)-methyl(4-methylphenyl)(naphthalen-1-yl)arsine, [α]D - 115.9� (c, 0.593 in CHCl3), and partly resolved [R-(R*,R*)]-2,3-diphenyloxiran.


1983 ◽  
Vol 61 (6) ◽  
pp. 1132-1141 ◽  
Author(s):  
Gordon William Bushnell ◽  
Roderick James Densmore ◽  
Keith Roger Dixon ◽  
Arthur Charles Ralfs

Synthesis and 31P nmr spectra of the complex cations, cis-[PtCl(L)(PEt3)2]+, L= theophylline, caffeine, or isocaffeine, and cis[Pt(isocaff)2(PEt3)2]2+ are reported. The crystal structure of cis-[PtCl(caffeine)(PEt3)2][BF4] is determined, space group [Formula: see text], a = 1.1766(6), b = 1.4428(5), c = 0.9002(4) nm, α = 97.28(4)°, β = 97.69(4)°, γ = 100.96(5)°, Dm = 1.649 g cm−1, the bond lengths are Pt—Cl= 233.4(4) pm, Pt—N = 215(1) pm, Pt—P = 225.4(5) pm (mean), and the residual R = 0.071. The crystal structure of cis-[Pt(isocaffeine)2(PEt3)2][BF4]2 is orthorhombic, space group Pbca, a = 2.317(3), b = 1.717(3), c = 2.130(3) nm, Dm = 1.574 g cm−3, with an opposing isocaffeine conformation, bond lengths Pt—N = 211(2) pm, Pt—P = 227.6(9) pm (mean), and R = 0.073. Both crystal structures contain approximately square planar Pt(II) coordination with the purine coordinated via an imidazole nitrogen. The structures are discussed as models for the possible involvement of [Formula: see text] chelation of guanine to platinum when platinum drugs act as antitumour agents, but there is no evidence that isocaffeine acts as an [Formula: see text] chelate.


1982 ◽  
Vol 35 (2) ◽  
pp. 341 ◽  
Author(s):  
DG Hay ◽  
MF Mackay

X-ray crystallographic analyses have defined the conformational detail in the title compounds. Crystals of 2,2'-(phenoxymethylene)bis(4-chloro-6-nitrophenol) (1), Cl9H12Cl2N2O7, are monoclinic: space group P21/n, a 8.616(1), b 16.214(1), c l3.727(1) �, β 92.13(1)� and Z 4. The triethylamine adduct of 2,2'-(benzyloxymethylene)bis(4-chloro-6-nitrophenol) (2),Et3N, C20H14Cl2N2O7,C6H15N, crystallizes in the monoclinic space group P21/c with a 9.454(1), b 11.911(2), c 25.392(2) �, ββ 109.96(1)� and Z 4. The structures were refined with diffractometer data measured with Cu Kα radiation to R 0.061 (1761 terms) for (1) and R 0.063 (1230 terms) for (2),Et3N. The methylenebisphenol moieties in the molecules of (1) and (2) adopt twist and butterfly conformations respectively. In (1), the dihedral angles between the perpendiculars to the plane of the C-C-C bridge and the phenol rings are 61.1(4) and 71.6(4)�; in (2), these angles have values of 88.0(8) and 85.6(7)�.


1996 ◽  
Vol 49 (4) ◽  
pp. 527 ◽  
Author(s):  
PT Gulyas ◽  
TW Hambley ◽  
PA Lay

The crystal structure of [ Ru ( terpy )( bpy )( pz )] (PF6)2 has been determined by X-ray diffraction methods and refined to a residual of 0.046 for 1855 independent observed reflections. The crystals are monoclinic, space group P 21/a, a 16.836(7), b 10.778(5), c l9.342(5) Ǻ, β 115.11(3)°. The coordination geometry around the ruthenium(II) ion is distorted octahedral, with the various Ru -N bond lengths indicative of considerable interligand steric strain. The Ru -N pyrazine bond is the longest within the structure, consistent with other evidence that n back-bonding to pyrazine is weak in the complex.


1982 ◽  
Vol 37 (12) ◽  
pp. 1584-1589 ◽  
Author(s):  
U. Ensinger ◽  
W. Schwarz ◽  
A. Schmidt

The crystal and molecular structures of tetraethyl- (1), tetra-η-propyl- (2) and tetra-nbutylammonium tetrachloroantimonate(III) (3) were determined by X-ray analysis. There are discrete Sb4Cl164- (1) and Sb2Cl82- (2 and 3) anions. The Sb-Cl bond lengths vary in the range between 234 and 326 pm, and are explained as in a three centre-four electron situation. The vibrational spectra of the anions are briefly discussed


1985 ◽  
Vol 63 (5) ◽  
pp. 1063-1067 ◽  
Author(s):  
Tristram Chivers ◽  
Richard T. Oakley ◽  
Roger Pieters ◽  
John F. Richardson

The sulphenyl chloride, Ph2CNSCl, prepared insitu from Ph2CNSiMe3 and sulphur dichloride, has been employed in the synthesis of Ph2CNSNSO and Ph2CNSNSNSNCPh2 by reaction with Me3SiNSO and Me3SiNSNSiMe3, respectively. An X-ray structural determination of Ph2CNSNSO shows it to consist of a planar cis-trans chain. The crystals are triclinic and belong to the space group[Formula: see text], a = 9.9078(8), b = 10.0967(9), c = 15.1682(14) Å, α = 78.646(7), β = 71.065(7), γ = 63.449(7)°, V = 1281.5(5) Å3, Z = 4. The final R and Rw values were 0.033 and 0.027, respectively. The π* → π* excitation energies for the RSNSO and RSNSS chromophores are compared for different R groups and discussed in the light of MNDO calculations on the model compounds HSNSX (X = S, O). The thermal decomposition of both Ph2CNSNSO and Ph2CNSNSNSNCPh2 produced S4N4 and Ph2CO or (Ph2CN)2S, respectively.


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