Interaction of diiodine with Et4todit = 4,5,6,7-tetrathiocino [1,2-b:3,4-b′]diimidazolyl-1,3,8,10-tetraethyl-2,9-dithione. Crystal and molecular structure of Et4todit•2I2

1989 ◽  
Vol 67 (9) ◽  
pp. 1416-1420 ◽  
Author(s):  
Davide Atzei ◽  
Paola Deplano ◽  
Emanuele F. Trogu ◽  
Francesco Bigoli ◽  
Maria Angela Pellinghelli ◽  
...  

Spectrophotometric studies on the reaction between diiodine and the title ligand in ratios ranging from 1:1 to 1:20 in CHCl3 have shown the formation of a 1:1 charge-transfer complex. A general computer program has been used to refine the equilibrium constant and the extinction coefficients simultaneously. In the solid state a 1:2 (donor to acceptor) complex has been isolated and an X-ray structure analysis of the compound indicated that the crystals are monoclinic, space group C2/c with a = 16.317(4), b = 13.912(3), c = 12.879(3) Å, β = 111.24(2)°, Z = 4.The molecular structure shows that two sulphur-thioamide atoms of the ligand act as donor with respect to two diiodine molecules. The structural data of the organic molecule of the complex and those of the free molecule are very similar. Keywords: diiodine, thioamides, charge-transfer, structure, equilibrium-constants.


1974 ◽  
Vol 4 (6) ◽  
pp. 361-371 ◽  
Author(s):  
J. N. Brown ◽  
L. D. Cheung ◽  
L. M. Trefonas ◽  
R. J. Majeste


1979 ◽  
Vol 34 (3) ◽  
pp. 434-436 ◽  
Author(s):  
A. Müller ◽  
S. Pohl ◽  
M. Dartmann ◽  
J. P. Cohen ◽  
J. M. Bennett ◽  
...  

Abstract The novel tri-nuclear metal-sulfur cluster [Mo3S(S2)6]2- can be obtained as its ammonium salt by the reaction of a Moiv containing aqueous solutions with polysulfide. Its crystal and molecular structure has been determined by a single crystal X-ray study. The crystals are monoclinic (space group Cm, with a = 11.577(6) Å, b = 16.448(7) Å, c = 5.716(2) Å, β = 117.30(3)°, V = 967.2 Å3 , Z = 2, dexptl. = 2.54(2) g/cm3 , dcal = 2.54 g/cm3). The structure consists of isolated [Mo3S(S2)6]2- units, with three Mo atoms at the vertices of a triangle. There are bridging as well as terminal S22--ligands lying above and below the Mo3-plane (bond distances: Mo-Mo = 2.722 Å, Mo-S(terminal) = 2.435, Mo-S(bridging) = 2.452, Mo3-S = 2.353(4) Å and S-S = 2.04 Å (mean values)).



1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.



1978 ◽  
Vol 56 (10) ◽  
pp. 1364-1367 ◽  
Author(s):  
M. J. Bennett ◽  
J. T. Purdham

1,2,4,5-Tetraphenyl-3,6-dicarbornethoxytricyclo[3.1.0.02,4]hexane crystallizes in the monoclinic space group P21/c with a = 10.044(4), b = 9.500(2), c = 14.172(4) Å, β = 104.38(2)°, and Z = 2. Using 1032 unique reflections with I > 3σ(I), the structural data were refined by full matrix least-squares techniques to R = 0.038. The molecule was found to be in the anti-configuration. All bond lengths within the highly strained central tricyclic framework were equal within experimental error and average 1.531 Å.



Author(s):  
ROGER GUILARD ◽  
VIRGINIE PICHON-PESME ◽  
HASSANE LACHEKAR ◽  
CLAUDE LECOMTE ◽  
ALLY M. AUKAULOO ◽  
...  

The synthesis and characterization of three monomeric aluminum porphycenes with anionic or σ-bonded axial ligands is reported. The investigated compounds are represented as ( EtioPc ) Al ( CH 3) and ( EtioPc ) AlX where EtioPc represents the dianion of etioporphycene and X = Cl − or OH −. Each synthesized complex was characterized by mass spectrometry. 1 H NMR, IR and UV-visible spectroscopies as well as by electrochemistry. Comparisons are made between the properties of complexes in the aluminum etioporphycene series and related chloro- or methyl σ-bonded Al ( III ) porphyrins containing octaethylporphyrin ( OEP ) or tetraphenylporphyrin ( TPP ) macrocycles. Comparisons are also made between the currently investigated compounds and a previously reported Al ( III ) μ-oxo dimer, [( EtioPc ) Al ]2 O . In addition, the crystal and molecular structure of ( EtioPc ) Al ( CH 3) was determined by X-ray diffraction. The molecular structure of this methyl-σ-bonded aluminum etioporphycene provides the first structural data for an aluminum porphycene compound. The aluminum(III) atom in ( EtioPc ) Al ( CH 3) is pentacoordinated and is located 0.54 Å from the plane of the four N -nitrogens.



1975 ◽  
Vol 53 (22) ◽  
pp. 3383-3387 ◽  
Author(s):  
Joseph Hubert ◽  
André L. Beauchamp ◽  
Roland Rivest

The crystal and molecular structure of dithiocyanato(triphenylarsine)mercury(II) has been determined from X-ray diffraction data. The crystals are monoclinic, space group P21/c, with a = 10.290(7), b = 21.199(23), c = 10.719(7) Å, β = 112.00(2)°, and Z = 4. The structure has been solved by the heavy-atom method and refined by block-diagonal least-squares calculations. The agreement factor R obtained for 2607 'observed' reflections is 0.030. The crystal consists of single molecules. The 'characteristic' coordination number of mercury is three, with two sulfur and one arsenic atoms at the apexes of a triangle. The nitrogen atoms of the thiocyanate groups are at 2.67 and 2.74 Å from the adjoining mercury atoms and therefore link the different molecules together.



1979 ◽  
Vol 57 (2) ◽  
pp. 174-179 ◽  
Author(s):  
A. Wallace Cordes ◽  
Paul F. Schubert ◽  
Richard T. Oakley

The crystal structure of 1,4-diphenyl-2,2′,3,3′,5,5′,6,6′-octamethylcyclo-1,4-diphospha-2,3,5,6-tetrasilahexane, (PhPSi2Me4)2, has been determined by single crystal X-ray diffraction. The crystals are monoclinic, space group P21/c, with a = 9.866(1), b = 11.921(1), and c = 11.324(2) Å, β = 104.31(1)°, Z = 2, and ρcalcd = 1.15 g/cm3. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.060 and Rw of 0.078, for 1173 reflections with intensities greater than 3σ. The (PhPSi2Me4)2 molecule lies on a crystallographic centre of symmetry, and the six-membered P2Si4 ring has a chair conformation with equatorial phenyl groups. The endocyclic angles at P (104.4(1)°) and Si (104.9(2)°) are intermediate between those found in cyclic hexaphosphine and hexasilane molecules, and the Si—Si and P—Si distances of 2.345(3) and 2.252(4) Å, respectively, correspond to single bond lengths, with no appreciable evidence for secondary pπ → dπ bonding between phosphorus and silicon. The Si—C (1.867(8) Å) and P—C (1.828(7) Å) bond lengths are also normal. The variations in the Si—P—C (101.6(2)°, 108.6(2)°), P—Si—C (range 106.2(3)–120.0(3)°), and Si—Si—C (range 105.8(3)–113.7(3)°) angles indicate that the positions of the exocyclic methyl and phenyl groups are influenced by both intra- and intermolecular steric forces.



1993 ◽  
Vol 58 (9) ◽  
pp. 2121-2127 ◽  
Author(s):  
Josef Přikryl ◽  
Bohumil Kratochvíl ◽  
Jan Ondráček ◽  
Jaroslav Maixner ◽  
Jiří Klicnar ◽  
...  

The title charge-transfer complex crystallizes in the ratio of two molecules of azo dyestuff to one molecule of naphthalene. The crystals are triclinic, space group P1, lattice parameters a = 7.953(1), b = 11.608(2), c = 11.717(2) Å, α = 101.89(2), β = 94.27(2), γ = 109.91(2)°, Z = 2. The structure was solved by direct methods and refined anisotropically to R = 0.054 for 1 768 unique observed reflections. Crystal packing is stabilized by van der Waals forces and partly by π-π stacking interaction among naphthalene, phenyl and pyridine ring of pyridon azo dyestuff.



1988 ◽  
Vol 66 (6) ◽  
pp. 1483-1489 ◽  
Author(s):  
Davide Atzei ◽  
Paola Deplano ◽  
Emanuele F. Trogu ◽  
Francesco Bigoli ◽  
Maria Angela Pellinghelli ◽  
...  

The reaction of some tetra-substituted dithiooxamides R2NC(S)C(S)NR2 (R = CH3:Me4dto; R = C2H5:Et4dto; R2N = OC4H8N:Mo2dto) with diiodine has been investigated by spectrophotometric methods in CHCl3. The formation in solution of 1:1 and 1:2 charge-transfer (c.t.) complexes between the reagents has been observed. A new computer program, derived from "SUPERQUAD" (P. Gans, A. Sabatini, and A. Vacca. J. Chem. Soc. Dalton Trans. 1195 (1985)), has been applied to evaluate the formation constants. The 1:2 c.t. complexes have been isolated in the solid state, and an X-ray structure analysis of the [OC4H8NC(S)C(S)NC4H8O]•2I2 compound indicated that the crystals are triclinic, space groups [Formula: see text], with a = 14.659(6), b = 15.111(6), c = 9.317(5) Å, α = 92.29(2), β = 99.71(2), γ = 99.48(2)° and Z = 4. In particular the torsion angle S—C—C—S (≈90°) shows that the conformation of the dithiooxamide is not trans.



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