Dimethyltellurium(IV) derivatives with mixed 1,1-dithio ligands. Crystal structures of Me2Te[S2CNMe2][S2COEt] and Me2Te[S2CNEt2][S2COMe]

1999 ◽  
Vol 77 (7) ◽  
pp. 1262-1273 ◽  
Author(s):  
John E Drake ◽  
Layla N Khasrou ◽  
Anil G Mislankar ◽  
Raju Ratnani
Keyword(s):  
Lone Pair ◽  
Mixed Ligand ◽  
Equatorial Position ◽  
X Ray ◽  
Cell Parameters ◽  
X Ray Crystallography ◽  
Secondary Interactions ◽  
Infrared And Raman Spectroscopy ◽  
Distorted Trigonal Bipyramid ◽  
Derivatives Of

Mixed ligand derivatives of Me2TeLL'2, where L = N,N-dialkyl dithiocarbamate or O,O-alkylene dithiophosphate and L' = O-alkyl dithiocarbonate, have been synthesized and characterized by elemental analysis, 1H, 13C, 31P, and 125Te NMR spectroscopy and infrared and Raman spectroscopy, and X-ray crystallography. Me2Te[S2CNMe2][S2COEt], 8: P[Formula: see text] (no. 2), with cell parameters a = 10.073(3) Å, b = 10.139(2) Å, c = 9.108(2) Å, α = 92.36(2)°, β = 115.55(2)°, γ = 111.19(2)°, V = 760.7(4) Å3, Z = 2, R = 0.0343, Rw = 0.0296. Me2Te[S2CNEt2][S2COMe], 9: P21/c (no. 14) with cell parameters a = 9.881(4) Å, b = 17.671(3) Å, c = 10.149(4) Å, β = 113.65(3)°, V = 1623.3(10) Å3, Z = 4, R = 0.0567, Rw = 0.0514. The immediate environment about tellurium in both molecules is essentially that of a saw-horse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. The S-Te-S angles in the two molecules are 166.87(6)° and 162.0(1)° for 8 and 9, respectively. In both molecules, the Te—S bonds to the dithiocarbamate groups are slightly shorter than those to dithiocarbonates. The dithiocarbamate groups are oriented to give secondary interactions involving the apparently terminal sulfur atoms resulting in Te—S distances of 3.205(2) and 3.277(4) Å, respectively, in 8 and 9. However, only in 9 is there a similar Te—S distance of 3.346(5) Å involving the S2COMe group because in 8, the OEt group of S2COEt, rather than the terminal S atom, is oriented toward Te. Key words: structure, tellurium, methyl, dithiocarbamates, dithiocarbonates, dithiophosphates.

Tetraorganodichalcogenoimidodiphosphinato derivatives of dimethyltellurium(IV) compounds. Crystal structures of Me2Te[(SPPh2)2N]2, Me2TeCl[(SPPh2)2N], Me2TeI[(SPPh2)2N], and Me2TeCl[(OPPh2)(SPPh2)N]

1999 ◽  
Vol 77 (3) ◽  
pp. 356-366 ◽  
Author(s):  
John E Drake ◽  
Robert J Drake ◽  
Anca Silvestru ◽  
Jincai Yang
Keyword(s):  
Sulfur Atom ◽  
Lone Pair ◽  
Axial Position ◽  
Equatorial Position ◽  
X Ray Diffraction ◽  
Cell Parameters ◽  
Distorted Octahedral ◽  
Multinuclear Nmr Spectroscopy ◽  
Distorted Trigonal Bipyramid ◽  
Derivatives Of

Isolation of Me2Te[(SPPh2)2N]2, Me2Te[(OPPh2)(SPPh2)N]2, and the halo derivatives Me2TeX[(SPPh2)2N] and Me2TeX[(OPPh2)(SPPh2)N], where X = Cl, Br, I, was attempted. Four of these were characterized by single crystal X-ray diffraction, while the formation of the others was confirmed by multinuclear NMR spectroscopy. Me2Te[(SPPh2)2N]2, 1; P21/n (No. 14) with cell parameters a = 14.908(3) Å, b = 11.122(5) Å, c = 30.384(6) Å, β = 92.67(2)°, V = 5032(2) Å3, Z = 4, R = 0.0661, Rw = 0.0696. Me2TeCl[(SPPh2)2N], 2; P[Formula: see text] (No. 2) with cell parameters a = 10.553(2) Å, b = 15.512(2) Å, c = 8.769(3) Å, α = 103.19(2)°, β = 94.27(2)°, γ = 85.76(2)°, V = 1391.3(7) Å3, Z = 2, R = 0.0377, Rw = 0.0328. Me2TeI[(SPPh2)2N], 4; P[Formula: see text] (No. 2) with cell parameters a = 10.954(3) Å, b = 15.580(3) Å, c = 8.751(3) Å, α = 103.49(2)°, β = 93.11(3)°, γ = 87.33(2)°, V = 1449.3(7) Å3, Z = 2, R = 0.0586, Rw = 0.0613. Me2TeCl[(OPPh2)(SPPh2)N], 6; P21/c (No. 14) with cell parameters a = 10.441(9) Å, b = 13.672(10) Å, c = 19.521(9) Å, β = 97.16(6)°, V = 2764(3) Å3, Z = 4, R = 0.0546, Rw = 0.0572. The immediate environment about Te is that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. In 1, 2, and 4, one sulfur atom of (SPPh2)2N occupies an axial position. If the second sulfur atom is included in the coordination sphere, then the environment about Te becomes distorted octahedral, for 1, and square pyramidal, for 2 and 4. By contrast, in Me2TeCl[(OPPh2)(SPPh2)N], 6, the oxygen atom, rather than sulfur, is bound to tellurium in the axial position, with the S atom, at best, having a very weak interaction with Te.Key words: structure, tellurium, methyl, tetraphenyldichalogenoimidodiphosphinates.

Synthesis, spectroscopic and structural studies of O-methyl and O-isopropyl monothiocarbonate (monoxanthate) derivatives of dimethyl-and diphenyltellurium(IV). Crystal structures of Me2Te[SCO2(i-Pr)]2, Ph2Te[SCO2(i-Pr)]2, Me2TeCl[SCO2Me], and Me2TeBr[SCO2(i-Pr)]

1996 ◽  
Vol 74 (11) ◽  
pp. 1968-1982 ◽  
Author(s):  
John E. Drake ◽  
Robert J. Drake ◽  
Layla N. Khasrou ◽  
Anil G. Mislankar ◽  
Raju Ratnani ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Key Words ◽  
Lone Pair ◽  
Supramolecular Interactions ◽  
Equatorial Position ◽  
Structural Studies ◽  
Cell Parameters ◽  
Distorted Trigonal Bipyramid ◽  
Derivatives Of ◽  
Oxygen Atoms

Monothiocarbonate derivatives of diorganotellurium(IV), R2Te[SCO2R′]2, and R2TeX[SCO2R′], where R = Me, Ph; R′ = Me, i-Pr; X = Cl, Br, and I, have been prepared and characterized by vibrational and 1H, 13C, and 125Te NMR spectroscopy. Me2Te[SCO2(i-Pr)]2 (2): P21/n (No. 14) with cell parameters a = 6.942(6) Å, b = 25.599(3) Å, c = 9.404(6) Å, β = 94.48(6)°, V = 1666(1) Å3, Z = 4, R = 0.0648, Rw = 0.0624; Ph2Te[SCO2(i-Pr)]2 (4): P21/n (No. 14) with a = 12.360(4) Å, b = 12.277(3) Å, c = 15.066(3) Å, β = 102.82(2)°, V = 2229.1(9) Å3, Z = 4, R = 0.0368, Rw = 0.0312; Me2TeCl[SCO2Me] (5); P21/c (No. 14) with a = 5.193(2) Å, b = 18.118(4) Å, c = 9.613(5) Å, β = 91.31(6)°, V = 904.2(6) Å3, Z = 4, R = 0.0396, Rw = 0.0361; and Me2TeBr[SCO2(i-Pr)] (8): P21/n (No. 14) with a = 11.701(2) Å, b = 6.250(2) Å, c = 16.152(2) Å, β = 98.43(1)°, V = 1168.4(4) Å3, Z = 4, R = 0.0369, Rw = 0.0325. In all molecules, the immediate environment about tellurium is that of the saw-horse structure in which the lone pair is assumed to be stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. In 2 and 5, the terminal oxygen atoms are oriented toward tellurium, whereas in 4, one O(i-Pr) group is oriented toward tellurium, as it is in 8. In the latter cases, the terminal oxygen atoms act as weak bridges to form a pseudo dimeric species in 4 and a pseudo polymer in 8. Supramolecular interactions in 2 and 5 lead to a sulfur-bridged dimer in the former and a chlorine-bridged polymer in the latter. Key words: structure, tellurium, dimethyl, diphenyl, monothiocarbonates.

Syntheses, characterization, and X-ray crystal structures of diorganotin(IV) derivatives of 2-pyridinethiolato-N-oxide

2003 ◽  
Vol 81 (10) ◽  
pp. 1070-1075 ◽  
Author(s):  
Chunlin Ma ◽  
Junhong Zhang ◽  
Rufen Zhang
Keyword(s):  
Crystal Structure ◽  
Stacking Interactions ◽  
X Ray ◽  
X Ray Crystallography ◽  
Nmr Data ◽  
Π Stacking ◽  
Oxide Crystal ◽  
Distorted Trigonal Bipyramid ◽  
Π Stacking Interaction ◽  
Derivatives Of

The diorganotin(IV) dichloride reacts with sodium 2-pyridinethiolato-N-oxide in a 1:1 ratio to produce [Me2SnCl(2-SpyO)] (1), [Et2SnCl(2-SpyO)] (2), [Bu2SnCl(2-SpyO)] (3), [Ph2SnCl(2-SpyO)] (4), and [(PhCH2)2SnCl(2- SpyO)] (5). The new complexes have been characterized by elemental analysis and IR and NMR (1H, 119Sn, and 13C) spectroscopy. On the basis of 119Sn NMR data the effective coordination number in solution is five. The structures 1 and 4 have been confirmed by X-ray crystallography. Crystals of 1 are triclinic with space group P[Formula: see text] and those of 4 are monoclinic, P21/n. The tin environment is a distorted trigonal bipyramid with the Cl and oxygen atoms in apical positions. Both complexes exhibit strong π–π stacking interactions. Key words: diorganotin, π–π stacking interaction, 2-pyridinethiolato-N-oxide, crystal structure.

A study of a variety of O,O-alkylene dithiophosphate derivatives of triphenyl-and diphenylgermane. Crystal structures of and

1995 ◽  
Vol 73 (7) ◽  
pp. 915-928 ◽  
Author(s):  
John E. Drake ◽  
Anil G. Mislankar ◽  
Raju Ratnani ◽  
Jincai Yang
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
Crystal Structures ◽  
Distorted Tetrahedron ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
X Ray Crystallography ◽  
Derivatives Of

The O,O-alkylene dithiophosphate derivatives of triphenyl- and diphenylgermane, [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] and [Formula: see text] have been prepared and characterized by infrared, Raman, and 1H, 13C, and 31P NMR spectroscopy, mass spectrometry, and, in three cases, X-ray crystallography. [Formula: see text] 1, crystallizes as monoclinic in the space group P21/a (No. 14) with the cell parameters a = 12.868(5) Å, b = 11.354(4) Å, c = 17.207(4) Å, β = 95.42(2)°, V = 2502(1) Å3, Z = 4, R = 0.0640, and Rw = 0.0585. [Formula: see text] 2, crystallizes as orthorhombic in the space group Pbca (No. 61) with the cell parameters a = 23.007(4) Å, b = 16.840(4) Å, c = 12.068(3) Å, V = 4657(3) Å3, Z = 8, R = 0.0502, and Rw = 0.0329. [Formula: see text] 3, crystallizes as monoclinic in the space group C2/c (No. 15) with the cell parameters a = 35.48(2) Å, b = 9.275(5) Å, c = 20.78(1) Å, β = 120.93(3)° V = 5866(5) Å3, Z = 8, R = 0.0674, and Rw = 0.0562. As with their methylgermanium analogues, the environment about germanium is essentially that of a distorted tetrahedron, with the terminal sulfur atoms oriented towards germanium rather than away from it, in contrast with analogous noncyclic dithiophosphatogermanes. The substituents on the atoms in both the five- and six-membered rings maintain their nonequivalence in solution, in contrast with tin analogues. Keywords: structure, germanium, diphenyl, triphenyl, cyclic dithiophosphates

Syntheses and Characterization of Two New Mixed-Ligand Bismuth(III) Complexes, Crystal Structure of [Bi(phen)2(NO3)(NCS)2(MeOH)]

2005 ◽  
Vol 60 (4) ◽  
pp. 389-392 ◽  
Author(s):  
Ali Morsali
Keyword(s):  
Lone Pair ◽  
Mixed Ligand ◽  
Bismuth Atom ◽  
Stacking Interactions ◽  
Coordination Geometry ◽  
Aromatic Rings ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses

Complexes [Bi(phen)2(NO3)(NCS)2(MeOH)] and [Bi(phen)2(NO3)2(NCS)] have been synthesized and characterized by their IR spectra and elemental analyses. The structure of the [Bi(phen)2(NO3)(NCS)2(MeOH)] complex has been confirmed by X-ray crystallography. The Bi atoms are unsymmetrically eight-coordinated, N6O2. The arrangement of the ligands does not show a gap in the coordination geometry around the Bi(III) ion, indicating that its lone pair of electrons is not active. The thiocyanate ligands are coordinated to the bismuth atom via the nitrogen atom. There is π-π stacking interactions between the parallel aromatic rings belonging to adjacent chains

scholarly journals Über Verbindungen subvalenter Hauptgruppenmetallkationen mit Dithiolaten, 4. Mitteilung [1] Die Kristallstrukturen der Verbindungen Pb[S(CN)C=C(CN)S] und (AsPh4)2{Pb[S(CN)C=C(CN)S]2} / Compounds of Subvalent Main Group Metal Cations with Dithiolates, Part 4 [1] Crystal Structures of Pb[S(CN)C=C(CN)S] and (AsPh4)2{Pb[S(CN)C=C(CN)S]2}

1989 ◽  
Vol 44 (12) ◽  
pp. 1531-1537 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Hermann Meske
Keyword(s):  
Crystal Structures ◽  
Complex Anion ◽  
Lone Pair ◽  
Equatorial Position ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Main Group Metal ◽  
Distorted Trigonal Bipyramid

The crystal structures of Pb[S(CN)C=C(CN)S] and (AsPh4)2{Pb[S(CN)C=C(CN)S]2} have been determined by X-ray diffraction. PbS2C4N2, crystallizes in the non-centrosymmetric space group P21 with a = 7.292(3), b = 7.420(3), c = 5.789(2) Å, β = 95.47(5)° and Ζ = 2. The lead atom is coordinated by three S atoms of dithioligands. The coordination sphere around Pb includes a stereochemically active lone-pair and is described as a distorted tetrahedron. (AsPh4)2[Pb(S2C4N2)2] crystallizes in the triclinic space group P1 with a = 17.205(3), b = 13.342(3), c = 12.059(2) Å, α = 106.15(7), β = 102.92(6), γ = 79.50(3)° and Z = 2. In the complex anion {Pb[S(CN)C=C(CN)S]2}2- the Pb-atom is located at a centre of a distorted trigonal bipyramid with a stereochemically active lone-pair in an equatorial position.

The Through-Bond Interaction of a Sulfur Lone Pair with Oxygenated Substituents in the Thiacyclohexane Framework

2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Crystal Structures ◽  
Bond Distance ◽  
Lone Pair ◽  
X Ray ◽  
Ester Derivative ◽  
Bond Interaction ◽  
Derivatives Of ◽  
Electron Demand

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.

The direct electrochemical synthesis of some metal derivatives of lapachol

1997 ◽  
Vol 75 (5) ◽  
pp. 499-506 ◽  
Author(s):  
E.H. De Oliveira ◽  
G.E.A. Medeiros ◽  
C. Peppe ◽  
Martyn A. Brown ◽  
Dennis G. Tuck
Keyword(s):  
Electrochemical Oxidation ◽  
Copper Atom ◽  
Electrochemical Synthesis ◽  
Acetonitrile Solution ◽  
Triclinic Space Group ◽  
X Ray ◽  
Metal Anode ◽  
X Ray Crystallography ◽  
Metal Derivatives ◽  
Derivatives Of

The electrochemical oxidation of a sacrificial metal anode (M = Zn, Cd, Cu) in an acetonitrile solution of 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthoquinone, lapachol, C15H14O3 (=HL) gives ML2. The results are in keeping with earlier work on direct electrochemical synthesis in related systems. Adducts with 2,2′-bipyridine (bpy) and N,N,N′,N′-tetramethylethanediamine (tmen) have also been prepared. The structure of the 2,2′-bipyridine adduct of Cu(lapacholate)2 has been established by X-ray crystallography. The parameters are triclinic, space group [Formula: see text], a = 12.748(59) Å, b = 13.859(49) Å, c = 11.770(59) Å, α = 108.30(4)°, β = 108.08(3)°, γ = 68.94(3)°, Z = 2, R = 0.059 for 2256 unique reflections. The copper atom is in a distorted CuN2O2O2′ environment. The mechanism of the formation of this Cu(lapacholate)2 is discussed. Keywords: electrochemical synthesis, lapachol, X-ray crystallography, copper(II) complex.

Triazene derivatives of (1,x-)diazacycloalkanes. Part VI. 3-({5,5-Dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines — Synthesis, characterization, and X-ray crystal structure

2006 ◽  
Vol 84 (10) ◽  
pp. 1294-1300 ◽  
Author(s):  
Keith Vaughan ◽  
Shasta Lee Moser ◽  
Reid Tingley ◽  
M Brad Peori ◽  
Valerio Bertolasi
Keyword(s):  
Crystal Structure ◽  
Significant Degree ◽  
Ion Trapping ◽  
Published Data ◽  
X Ray ◽  
X Ray Crystallography ◽  
Diazonium Ion ◽  
Derivatives Of ◽  
C Nmr

Reaction of a series of diazonium salts with a mixture of formaldehyde and 1,2-diamino-2-methylpropane affords the 3-({5,5-dimethyl-3-[2-aryl-1-diazenyl]-1-imidazolidinyl}methyl)-4,4-dimethyl-1-[2-aryl-1-diazenyl]imidazolidines (1a–1f) in excellent yield. The products have been characterized by IR and NMR spectroscopic analysis, elemental analysis, and X-ray crystallography. The X-ray crystal structure of the p-methoxycarbonyl derivative (1c) establishes without question the connectivity of these novel molecules, which can be described as linear bicyclic oligomers with two imidazolidinyl groups linked together by a one-carbon spacer. This is indeed a rare molecular building block. The molecular structure is corroborated by 1H and 13C NMR data, which correlates with the previously published data of compounds of types 5 and 6 derived from 1,3-propanediamine. The triazene moieties in the crystal of 1c display significant π conjugation, which gives the N—N bond a significant degree of double-bond character. This in turn causes restricted rotation around the N—N bond, which leads to considerable broadening of signals in both the 1H and 13C NMR spectra. The molecular ion of the p-cyanophenyl derivative (1b) was observed using electrospray mass spectrometry (ES + Na). The mechanism of formation of molecules of type 1 is proposed to involve diazonium ion trapping of the previously unreported bisimidazolidinyl methane (13).Key words: triazene, bistriazene, imidazolidine, synthesis, X-ray crystallography, NMR spectroscopy.

scholarly journals NMR and X-ray studies of apetalic acid isolated from Calophyllum brasiliense and of its chiral amides

2021 ◽  
Author(s):  
Marie-Rose Van Calsteren ◽  
Ricardo Reyes-Chilpa ◽  
Chistopher K Jankowski ◽  
Fleur Gagnon ◽  
Simón Hernández-Ortega ◽  
...  
Keyword(s):  
Antimycobacterial Activity ◽  
Side Chain ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Rain Forests ◽  
X Ray ◽  
X Ray Crystallography ◽  
Calophyllum Brasiliense ◽  
Derivatives Of

The tropical tree Calophyllum brasiliense (Clusiaceae) grows in the rain forests from Brazil to Mexico. Its leaves, as well as those of other Calophyllum species, are rich sources of chromanone acids, such as apetalic acid, isoapetalic acid, and their derivatives. Apetalic acid has shown significant antimycobacterial activity. The biological activity of apetalic acid has been related to the configuration of three asymmetric centers and the stereochemistry of the molecule; however, the C-19 configuration in the acidic side chain has not been fully resolved. For this reason, the unequivocal determination of the absolute configuration by means of X-ray crystallography in a sample of unique homogeneous apetalic acid stereoisomer was the most important point to start this study. We prepared some chiral amides using the carboxyl group. We determined the C-19 stereochemistry of apetalic acid, and its specific chiral derivatives, using NMR, X-ray diffraction methods, and molecular mechanics. Finally, we observed that steric hindrance in the side chain of apetalic acid leads to restriction of rotation around the pivotal link C-10 and C-19 establishing chiral centers at C2(R), C3(S), and C19(R). We were able to separate derivatives of these two high-rotatory-barrier conformers of apetalic acid by forming diastereoisomeric amides with phenylglycine methyl ester having a chiral center at C-2’. Our results allowed the conclusion of the existence of atropisomerism in the apetalic acid molecule.

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