The crystal and molecular structures of the ligand (E)-Pyridine-2-carbaldehyde Pyridin-2'-ylhydrazone and the palladium(II) complex Chloro[(E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazonato]palladium(II) which involves the coordination of the ligand in its anionic form

1984 ◽  
Vol 37 (4) ◽  
pp. 739 ◽  
Author(s):  
AT Casey ◽  
BF Hoskins ◽  
IP Traverso

The crystal and molecular structures of the ligand (E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazone hydrate and its complex chloro[(E)-pyridine-2-carbaldehyde pyridin-2'-ylhydrazonato]palladium(II) have been determined by single-crystal three-dimensional X-ray diffraction techniques. Crystals of the ligand are monoclinic with space group P 21/c. The unit cell, which contains four molecules of ligand together with approximately ten disordered water molecules, has the dimensions a 17.762(4), b 3,8717(11), c 18.503(4) Ǻ and β 107.99(2)°. Crystals of the complex are triclinic with space group P1, and the unit cell has the dimensions a 6.9721(3), b 9.0739(11), c 9.1304(9) Ǻ, α81.116(9), β 88.778(8) and γ 81.392(8)°; Z = 2. The ligand structure was solved by direct methods and refined with anisotropic thermal parameters for all non-hydrogen atoms and isotropic thermal parameters for hydrogen and solvent atoms. The complex structure was solved by conventional Fourier methods and refined with anisotropic thermal parameters for all non-hydrogen atoms. A full-matrix least-squares method was employed for both structures based on 1295 and 2224 statistically significant reflections giving final values of R 0.061, Rw 0.068 and R 0.028, Rw 0.030 for the ligand and complex respectively. The structure analysis of the ligand shows definite evidence of delocalization of lone pair electrons in the hydrazine moiety. The ligand in its anionic form coordinates in a tridentate manner to the palladium atom in the complex through the two pyridine nitrogen atoms and the distal nitrogen of the hydrazine residue. A square-planar array is formed by a chlorine atom occupying the fourth position. Molecular dimensions suggest that the lone pair on the proximal nitrogen is delocalized over the entire molecule. Standard valence-bond and 'increased valence' methods have been applied in order to determine resonance schemes consistent with the observed structures of both the ligand and its complex.


1990 ◽  
Vol 45 (8) ◽  
pp. 1167-1176 ◽  
Author(s):  
Alfons Möhlenkamp ◽  
Rainer Mattes

The reaction of NaReO4 with thiobenzoylhydrazine yields Re(NHNC(S)Ph)3- DMF (1). With ReOCl3(PPh3)2 thiobenzoylhydrazine reacts to give Re(NHNC(S)Ph)3 · OPPh3 (2) and in the presence of HCl to yield [Re(NHNC(S)Ph)(NHNHC(S)Ph),]Cl · 1/3 C2H5OH -1 /3 H2O (3). The structures of 1-3 have been determined. 1: monoclinic, space group P2,/c, a = 1150.1(9), b = 2050.0(9), c = 1181.0(8) pm, β = 109.62(5)°, Z = 4, 2980 reflections, R = 0.055; 2: trigonal, space group R 3, a = 1399.8(1), c = 1684.0(1) pm, Z = 3, 1419 reflections, R = 0.033; 3: monoclinic, space group P2,/c, a = 1446.8(3), b = 3220.7(5), c = 1727.1(4) pm, β = 108.42(2)°, Z = 12, 6112 reflections, R = 0.062. In 1 and 2 three N,S-chelating ligands NHNR (R = C(S)Ph) are coordinated to the central rhenium atom. The ligand structure is intermediate between a diazene and a hydrazido(2–) structure. In 3 each rhenium atom is coordinated by one NHNR and two NHNHR ligands, all N,S-chelating. The latter can be considered as protonated diazene ligands. The unit cell contains three isomeric coordination polyhedra.



1987 ◽  
Vol 40 (5) ◽  
pp. 907 ◽  
Author(s):  
GB Deacon ◽  
BM Gatehouse ◽  
SN Platts ◽  
DL Wilkinson

The crystal structures of tris (η5-cyclopentadienyl) (pyridine) samarium(III), monoclinic, space group P21/c, a 10.906(4), b 8.636(2), c 17.825(3) �, β 96.44(2)�, Z 4, R 0.027 and Rw 0.032 for 3619 'observed' reflections, and tris (η5-cyclopentadienyl)(pyridine)neodymium(III), monoclinic, space group P21 / c, a 14-206(4), b 8.619(2), c 15.190(7) �, β 107.38(2)�, Z 4, R 0.035 and R, 0.039 for 2677 'observed' reflections have been determined. Both compounds have pseudotetrahedral geometry with a coordination number of 10 for the lanthanoid metal but there is a difference in the coordination of pyridine and in unit cell packing between the two structures.



Author(s):  
G. Dewald ◽  
M. Hanack ◽  
E.-M. Peters ◽  
L. Walz

AbstractThe crystal and molecular structures of dimorphic 10,10′-(1,4-phenylene-dimethylidene)-bis-9,10-H-anthracenone (1) have been determined using X-ray diffraction data. The compound crystallizes either in the monoclinic space groupSince all non-hydrogen atoms are of pure



1986 ◽  
Vol 39 (12) ◽  
pp. 1983 ◽  
Author(s):  
AJ Edwards ◽  
BF Hoskins ◽  
G Winter

The crystal and molecular structures of bis (O- benzylxanthato )nickel(II), Ni( bzxa )2, and the benzene clathrate of its 1,10-phenanthroline adduct, Ni( bzxa )2( phen ).C6H6, are reported. Crystals of Ni( bzxa )2 are orthorhombic, with the space group P bca. There are four molecules per unit cell, which has dimensions a 6.961(1), b 35.008(8), c 7.277(2)Ǻ. The refinement converged with R 0.031 and Rw 0.037 after use of 1732 independent reflections for which I ≥ 2σ(I). Asymmetry of the nickel-sulfur bonds is observed. The adduct crystallizes in the space group C2/c. There are four molecules each of the adduct and benzene per unit cell, which has dimensions a 7.133(3), b 18.196(5), c 24.282(5)Ǻ, β 97.01(2)°. The refinement converged with R 0.064 and Rw 0.052 after use of 1123 independent reflections for which I ≥ 2σ(I). The packing clearly indicates that this host-guest compound is of the clathrate type.



1984 ◽  
Vol 37 (10) ◽  
pp. 1991 ◽  
Author(s):  
SW Cowan ◽  
BF Hoskins ◽  
ERT Tiekink

The crystal and molecular structures of the title compounds, (C6H11)2PC(S)N(H)C6H5(1) and (C6H5)2PC(S)N(H)C6H5(2) have been determined by single-crystal three-dimensional X-ray diffraction techniques. Crystals of (1) are monoclinic, space group P21/c, with eight molecules in the unit cell of dimensions a 20.541(4), b 17.784(2), c 10.2564(9) � and β 94.54(1)�; (2) crystallizes in the triclinic space group P1 with two molecules in the unit cell which has the dimensions a 9.242(2), b 9.994(3), c 10.373(3) �, α 68.56(2), β 71.21(2) and γ 86.00(2)�. Both structures were refined by a least-squares procedure, applying anisotropic thermal parameters to all non-hydrogen atoms, with the use of 3119 and 2971 statistically significant reflections for (1) and (2) respectively; final R 0.055 for (1) and R 0.061 (Rw 0.062) for (2). The N, C(l), S moieties of both (1) and (2) display features consistent with the delocalization of π-electrons. There are notable differences in some of the bond angles between (I) and (2) which have been attributed to conformational effects arising from variations in steric pressures; this may account for the observed differences in reactivity between the two compounds.



1986 ◽  
Vol 39 (4) ◽  
pp. 547 ◽  
Author(s):  
SW Cowan ◽  
D Dakternieks ◽  
RW Gable ◽  
BF Hoskins ◽  
CL Rolls ◽  
...  

The crystal and molecular structures of the title compounds, [CdI2(LH)]2, (1), [HgCl2(LH)]2.CH2Cl2(2), and HgCl2(LH)2(3)[where LH = dicyclohexylphosphino-N-phenyl-thioformamide,* (c-C6H11)2PC(S)N(H)Ph] have been determined by single-crystal X-ray diffraction techniques. Crystals of (1) are monoclinic, space group P21/n, a 13.051(2), b 10.183(1), c 18.106(1)Ǻ and β 101.55(8)° with Z 2; R and Rw were 0.047 and 0.044 respectively for 2320 unique, observed reflections. The unit cell contains two equivalent centrosymmetric, halogen-bridged cadmium dimers. Crystals of (2) are triclinic, space group Pī, with a 10.668(4), b 14.978(3), c 16.838(4)Ǻ, and α 111.80(2), β 101.03(2), γ 92.06(2)° with Z 2; R and Rw were 0.069 and 0.067 respectively for 3379 unique observed reflections. The structure shows two independent centrosymmetric halogen-bridged dimers within the unit cell. Crystals of (3) are monoclinic, space group C2/c, a 24.719(6), b 12.247(3), c 26.818(6) Ǻ, and β 94.62(2)° with Z 8; R and Rw were 0.075 and 0.071 respectively for 2698 unique, observed reflections. The structure shows the complex to be monomeric. In all three compounds the metal atom is in an approximately tetrahedral environment with the potentially multidentate ligand, LH, coordinating only through the phosphorus atom. The mercury compounds show a much larger deviation from ideal tetrahedral geometry than does the cadmium compound.



1987 ◽  
Vol 65 (7) ◽  
pp. 1676-1680 ◽  
Author(s):  
Alan Shaver ◽  
James M. McCall ◽  
Victor W. Day ◽  
Sarah Vollmer

The crystal and molecular structures of (η5-C5H5)2ZrS5, 2, and (η5-C5H5)HfS5, 3, have been determined by single crystal diffractometry methods. Both compounds crystallized with four molecules in a monoclinic unit cell of dimensions: a = 8.984(3) Å, b = 13.336(4) Å, c = 11.421(2), β = 93.10(2)° for 2, and a = 9.012(2) Å, b = 13.291(2) Å, c = 11.381(2) Å, β = 93.25(1)° for 3; the space group is P21/n for both. These crystals of 2 and 3 are thus isomorphous with those of (C5H5)2TiS5, 1, studied by Epstein etal. (3a). The structures of all three complexes are very similar consisting of a cyclohexane-like six-membered MS5 ring with two C5H5 rings attached to the metals in an axial and equatorial position. The coordination spheres of 2 and 3 are less crowded than that of 1. The consequences of this are discussed with respect to the barriers to ring inversion in these complexes.



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.



1997 ◽  
Vol 75 (12) ◽  
pp. 1830-1843 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Jörg Metge ◽  
Steven J. Rettig ◽  
James Trotter

The syntheses of a number of aromatic aldonitrones of N-(2-hydroxyphenylmethyl)hydroxylamine and their subsequent reactions with diphenylborinic or carboxylic acid derivatives are reported. Crystals of 8-(4-dimethylaminophenylmethylene)-6,6-diphenyl-5,7-dioxa-8-azonia-6-borata-5H-6,7,8,9-tetrahydrobenzocycloheptene, 2b, are triclinic, a = 10.6802(8), b = 11.1809(4), c =10.1520(3) Å, α = 105.847(3)°, β = 92.567(4)°, γ = 84.610(5)°, Z = 2, space group PĪ, and those of C-(4-dimethylaminophenyl)-N-(2-hydroxyphenylmethyl)nitrone, 6e, are monoclinic, a = 12.2319(8), b = 7.071(1), c = 17.2005(9) Å, β = 107.520(4)°, Z = 4, space group P21/a. The structures were solved by direct methods and refined by full-matrix least-squares procedures to R = 0.035 and 0.032 (Rw = 0.036 and 0.032) for 3379 and 1800 reflections with I ≥ 3σ(I), respectively. Compound 2b is representative of a new type of heterocyclic B,N-betaine. The solid state structure of 6e (the precursor to 2b) shows that only small topological changes, but significant changes in the electron distribution, occur upon the formation of the diphenylboron chelate. Keywords: aromatic aldonitrones, organoboron compounds, crystal structures.



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.



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