The structural features of a tetrahedral 1,3-monothiolate complex: The crystal and molecular structure of Bis(ethyl 3-mercaptobut-2-enoato)zinc(II)

1977 ◽  
Vol 30 (5) ◽  
pp. 993 ◽  
Author(s):  
BF Hoskins ◽  
CD Pannan
Keyword(s):  
Molecular Structure ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Lone Pair ◽  
Structural Features ◽  
The Other ◽  
Zinc Atom ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Mean Values

The crystal and molecular structure of bis(ethy 3-mercaptobut-2- enoato)zinc(II) has been determined by single-crystal X-ray diffraction techniques. Solved by conventional Patterson and Fourier methods the structure was refined by a least-squares method employing anisotropic thermal parameters to all non-hydrogen atoms to R and Rw values of 0.040 and 0.046 respectively. The complex crystallizes in the monoclinic space group P21/c with four molecules in a unit cell of dimensions a 11.107(1), b 18.239(2) and c 8.438(1) Ǻ and β 107.7(1)�. The intensities of 2274 independent and statistically significant [I ≥ 3σ(I)] reflections with θ values ≤ 70� were measured by counter methods using nickel- filtered Cu Kα radiation. The crystals comprise discrete monomeric molecules with the zinc atom bonded to two sulphur atoms and two oxygen atoms giving a coordination arrangement which is substantially distorted from an ideal tetrahedron. The mean values for the Zn-S and Zn-O bond distances are 2.247(1) and 2.007(3) Ǻ respectively and the average S-Zn-O intraligand bond angle is 99.25(8)�. The geometries of the ligands differ in two ways. Firstly, the two ethyl groups adopt differing conformations and secondly, while one ligand moiety is essentially planar with the zinc atom displaced about 0.1 Ǻ from that plane, the displaced atom in the other ligand is the carbon bonded to the sulphur atom and not the metal which is, in this instance, coplanar with the other members of the ring. Bond distances in each chelate ring indicate aromatic character with a lone pair of electrons on the ethoxy-oxygen participating in the delocalization.

Crystal Structure of (NH4)2[Mo3S(S2)6] Containing the Novel Isolated Cluster [MO3S13]2-

1979 ◽  
Vol 34 (3) ◽  
pp. 434-436 ◽  
Author(s):  
A. Müller ◽  
S. Pohl ◽  
M. Dartmann ◽  
J. P. Cohen ◽  
J. M. Bennett ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Aqueous Solutions ◽  
Single Crystal ◽  
Ammonium Salt ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
The Novel ◽  
Mean Values ◽  
X Ray

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)).

Crystal and molecular structure of a cobalt(III) ammine complex of 2-Amino-4-imino-2-methylpentanoic acid

1975 ◽  
Vol 28 (4) ◽  
pp. 729 ◽  
Author(s):  
GB Robertson ◽  
PO Whimp
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Complex Cation ◽  
Three Dimensional ◽  
Cobalt Atom ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Ammine Complex ◽  
Coordination Sites ◽  
Acid Ligand

The crystal and molecular structure of a cobalt(III) ammine complex of 2-amino-4-imino-2-methyl-pentanoic acid, [Co(NH3)3{HN=C(CH3)CH2C(CH3)(NH2)(CO2)}]S2O6, has been determined from three-dimensional X-ray data collected by counter methods. The complex crystallizes in the monoclinic space group P21/c (C52h, No. 14), with a = 7.576(4), b = 18.209(7), c = 14.068(6) Ǻ, β = 125.25(2)�, Z = 4. The structure was solved by conventional Patterson and Fourier methods, and was refined by block-diagonal least-squares methods to weighted and unweighted 12-factors of 0.041 and 0.040 respectively, for the 1479 unique reflections having I/σ(I) ≥ 3.0. All hydrogen atoms have been located and refined. The complex cation is essentially octahedral about the central cobalt atom with three amine groups occupying mutually cis coordination sites; the three remaining sites at the cobalt atom are occupied by the tridentate 2-amino-4-imino-2-methylpentanoic acid ligand. The Co-O distance is 1.914(4) Ǻ, while the Co-N(imine) distance is 1.924(5) Ǻ. The Co-N(NH3) distances range from 1.968(5) to 1.979(5) Ǻ, and are equal within experimental error. Within the tridentate 2- amino-4-imino-2-methylpentanoic acid ligand, the C=N distance is 1.252(7) Ǻ, while at the carboxyl group the ?free? C-O distance [1.233(6) Ǻ] is significantly shorter than the distance from the carbon to the coordinated oxygen atom [1.270(7) Ǻ]. In the S2O6 counter anion, the S-S distance is 2.112(2) Ǻ, and the S-O distances range from 1.434(6) to 1.457(4) Ǻ, averaging 1.439 Ǻ.

The crystal and molecular structure of streptomycin oxime selenate tetrahydrate

1978 ◽  
Vol 359 (1698) ◽  
pp. 365-388 ◽  
Keyword(s):  
Molecular Structure ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Water Molecules ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Glycosidic Bonds ◽  
Compound C ◽  
Cell Dimensions ◽  
Network Of Hydrogen Bonds

The crystal and molecular structure and absolute configuration of the antibiotic streptomycin have been determined by an X-ray study of the hydrated oxime selenate. The compound (C 21 H 40 N 8 O 12 . 1 1/2 H 2 SeO 4 .4H 2 O) crystallizes in the monoclinic space group C 2, with cell dimensions a = 17.10(1), b = 14.36(1), c = 16.13(1)Å∥, β = 108.0(2)°; Z = 4 The structure was solved by the heavy-atom method, by using 3236 visually-estimated intensities, and refined to a conventional R of 0.086. The analysis has confirmed that streptomycin consists of three fragments, an N -methyl- α-L-glucosamine ring, an α-L-streptose and a streptidine ring, linked together by two glycosidic bonds. The crystal structure contains an elaborate network of hydrogen bonds linking selenate and streptomycin oxime ions and water molecules, analysis of which, though somewhat hampered by inability to observe the hydrogen atoms experimentally, reveals a disordered hydrogen bond occurring between two diad-related water molecules.

Preparation and 31P NMR characterization of N-bonded complexes of platinum(II) with a phosphadithiatriazine: X-ray structure of trans-PtCl2(Pet3)(η1-N-Ph2PS2N3)

1992 ◽  
Vol 70 (10) ◽  
pp. 2602-2606 ◽  
Author(s):  
Tristram Chivers ◽  
Robert W. Hilts ◽  
Ian H. Krouse ◽  
A. Wallace Cordes ◽  
Randal Hallford ◽  
...  
Keyword(s):  
Nitrogen Atom ◽  
Free Ligand ◽  
Heterocyclic Ring ◽  
Structural Features ◽  
The Other ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Absorption Bands ◽  
X Ray ◽  
Nmr Characterization

The reaction of Ph2PS2N3 with [Pt2(μ-Cl)2(PEt3)4][BF4]2 or [PtCl2(PEt3)]2, in dichloromethane at 23° C produces the 1:1 adducts cis-[PtCl(PEt3)2(Ph2PS2N3)][BF4], 3, and trans-[PtCl2(PEt3)(Ph2PS3N2)], 4, respectively, in good yields. The 31P NMR data for 3 and 4 indicate that (i) the platinum is attached to a nitrogen atom adjacent to phosphorus in both these adducts, (ii) the PEt3 ligands in 3 are in mutually cis positions, and (iii) the PEt3 ligand in 4 is trans to the heterocyclic nitrogen. These structural features were confirmed by an X-ray analysis of 4. Crystals of 4 are monoclinic, space group P21/c, with a = 14.920(3) Å, b = 8.966(5) Å, c = 19.103(5) Å, β = 109.32(2)°, V = 2411.6(16) Å3, and Z = 4. The least-squares refinement with anisotropic thermal parameters for all non-hydrogen atoms converged at R = 0.050 and Rw = 0.053. The Pt—N bond length is 2.122(15) Å and the coordinated nitrogen atom is lifted ca. 0.63(2) Å out of the plane containing the other heterocyclic ring atoms. The attachment of a platinum(II) centre to the PN3S2 ring perturbs the S—N bond lengths significantly. The S—N distance involving the coordinated nitrogen is 1.672(16) Å, while the other S—N distances are 1.631(19), 1.555(19), and 1.562(19) Å, indicative of a localized sulfur diimide (-N=S=N-) structure. The UV–visible spectra of 3 and 4 in CH2Cl2 exhibit absorption bands at 514 and 528 nm, respectively, but dissociation of these adducts to give the free ligand Ph2PS2N3 occurs readily in dilute solution.

The Crystal and Molecular Structure of trans-Dichloro-mer-trans-bis (triisopropylphosphine)(phosphine)hydridoiridium(III)

1995 ◽  
Vol 48 (7) ◽  
pp. 1277 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Molecular Structure ◽  
Transition Metal ◽  
Crystal And Molecular Structure ◽  
Structure Refinement ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Hydrogen Atoms ◽  
Full Matrix ◽  
X Ray ◽  
Molecular Dimensions

The structure of mer-trans-(PPri3)2(PH3)H-trans-Cl2IrIII (1) (Pri = isopropyl), the second third-row transition-metal-PH3 complex to be so characterized, has been determined by single-crystal X-ray diffraction analysis. Crystals are monoclinic, space group C 2/c with a 21.701(2), b 8.735(1), c 15.594(1) Ǻ, β 119.57(1)° and Z 4. Structure refinement by full-matrix least-squares analysis (2811 reflections, 113 parameters) converged with R = 0.016 and Rw = 0.022. Molecules exhibit crystallographically imposed C2 symmetry. The C2 axis passes through the iridium, hydride and PH3 phosphorus atoms, and requires the PH3 hydrogen atoms to be disordered. Important molecular dimensions are Ir-PPri3 2.371(1) Ǻ, Ir-PH3 2.362(1) Ǻ, Ir-Cl 2.374(1) Ǻ and P- Ir -P(trans) 163.21(3)°.

Crystal and molecular structure of (RS,RS)-Tetraammine(4,5-dihydroxy-4,5-dimethyl-1-pyrroline-2-carboxylato)cobalt(III) perchlorate

1975 ◽  
Vol 28 (10) ◽  
pp. 2129 ◽  
Author(s):  
GB Robertson ◽  
PO Whimp
Keyword(s):  
Molecular Structure ◽  
Hydrogen Atom ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Methyl Groups ◽  
Monoclinic Space Group ◽  
Hydrogen Atoms ◽  
Steric Strain ◽  
X Ray ◽  
R Factors

The structure of a cobalt(III) tetraammine complex of 4,5-dihydroxy- 4,5-dimethyl-1-pyrroline-2-carboxylic acid (abbreviated as hmpc), (RS,RS)-[Co(NH3)4(hmpc)] (ClO4)2,H2O, has been determined from three- dimensional X-ray data collected by counter methods. Crystals are monoclinic, space group P21/c, with a 11.984(5), b 8.836(4), c 19.609(7) Ǻ, β 110.58(2)�, Z 4. The structure has been refined to weighted and unweighted R-factors of 0.068 and 0.063, respectively, for the 1616 independent reflections with I/σ(I) ≥ 3.0. Hydrogen atoms could not be located and have not been included in the scattering model. There is considerable steric strain within the substituted pyrroline ligand, and the C=N distance is 1.293(8) Ǻ. Surprisingly, the methyl groups in the 4- and 5-positions are in a cisoid configuration (the torsion angle for the methyl groups about the 4-5 bond is 39.5�), and consequently the hydroxyl oxygen atoms are close [O-O distance, 2.583(8) Ǻ]; this suggests that there may be a bridging hydrogen atom.

Rhodium induced titanium–sulfur bond cleavage: crystal and molecular structure of ((COD)Rh(μ-SMe))2

1990 ◽  
Vol 68 (4) ◽  
pp. 565-569 ◽  
Author(s):  
Teresa A. Wark ◽  
Douglas W. Stephan
Keyword(s):  
Molecular Structure ◽  
Ligand Exchange ◽  
Crystal And Molecular Structure ◽  
Bond Cleavage ◽  
Structural Data ◽  
Structural Features ◽  
Monoclinic Space Group ◽  
Metal Metal ◽  
Early Late ◽  
Sulfur Bond

Reactions of Ti(III) and Ti(IV) thiolates with Rh complexes have been investigated. In the reaction of Cp2Ti(SMe)2 and [(COD)2Rh]BF4 or [(COD)Rh(sol)2]PF6, thiolate abstraction yields ((COD)Rh(μ-SMe))2, 1. Reaction of (Cp2Ti(μ-SMe))2 with ((COD)Rh(μ-Cl))2 results in ligand exchange affording (Cp2Ti(μ-Cl))2 and 1. The complex 1 crystallizes in the monoclinic space group P21/n, with a = 8.551(2) Å, b = 10.058(3) Å, c = 22.187(4) Å, β = 92.54(1)°, Z = 4, and V = 1906(1) Å3. The structural data show a relatively short approach between the Rh centres (2.948 Å) and between the bridging sulfur atoms (2.888 Å). The implications of these structural features in terms of metal–metal and sulphur–sulfur bonding are discussed. In addition, the implications of these results with respect to the formation of thiolato-bridged, early–late heterobimetallics is considered. Keywords: thiolate abstraction, rhodium thiolate bridged dimer.

The Crystal and Molecular Structure of Penta-P-tolylantimony, (p-CH3C6H4)5Sb

1973 ◽  
Vol 51 (17) ◽  
pp. 2952-2957 ◽  
Author(s):  
C. Brabant ◽  
J. Hubert ◽  
A. L. Beauchamp
Keyword(s):  
Molecular Structure ◽  
Solid State ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
The Other ◽  
Monoclinic Space Group ◽  
R Factor ◽  
Equatorial Bond ◽  
Derivatives Of ◽  
Heavy Atom Method

Penta-p-tolylantimony crystals are monoclinic, space group P21/c, with a = 14.545(5), b = 4(6), c = 19.754(8) Å, β = 122.88(4)°, and Z = 4. The structure was solved by the standard heavy-atom method and anisotropic refinement on 1677 independent observed reflections led to a conventional R factor of 0.051. Unlike pentaphenylantimony, which is known to exist as square pyramidal molecules in the crystal, the corresponding penta-p-tolyl derivative exhibits the more common trigonal bipyramid structure. The Sb—C equatorial bond length average, 2.16 Å, is significantly shorter than the axial average, 2.26 Å. Two of the C—Sb—C bond angles in the equatorial plane (113, 130°) differ considerably from 120°, but the other angles around antimony are normal. Packing forces appear to play a determining role in the structures observed for penta-aryl derivatives of antimony in the solid state.

The Crystal and Molecular Structure of trans-Dichloro-mer-tris(dimethylphenyl-phosphine)hydridoiridium(III) by X-Ray and Neutron Diffraction

1987 ◽  
Vol 40 (6) ◽  
pp. 1043 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker
Keyword(s):  
Molecular Structure ◽  
Neutron Diffraction ◽  
Crystal And Molecular Structure ◽  
Heavy Atom ◽  
Monoclinic Space Group ◽  
Neutron Data ◽  
Mean Values ◽  
X Ray ◽  
Hydride Ligand ◽  
The Difference

The crystal and molecular structure of mer -(PMe2Ph)3H- trans-Cl2IrIII (1) has been determined by single-crystal X-ray and neutron diffraction analyses. Crystals are monoclinic, space group P1, with a 8.91 9(4), b 9.895(4), c 12.269(6) �, α 70.33(4), β 81.75(4), γ 88.26(4)�, Z 2. The structure was solved by conventional heavy atom methods and refined by full-matrix least-squares analyses to final R values of 0.067 (X-ray data, R = ∑// Fo/-/Fc2/∑Fo/, 7516 independent reflections) and 0.086 (neutron data, R = ∑/Fo2- Fc2/∑ Fo2 2290 independent reflections). Weighted mean values for metal-ligand distances are Ir -P(trans to H) 2.365(2) �, Ir -P(trans to PMe2Ph) 2.329(2) � and Ir -Cl(trans to Cl) 2.402(2) and 2.364(2) �. The iridium-hydrogen bond [1.616(7) �] is trans-lengthened, vis-a-vis Ir -H trans to Cl, by c. 0.05 �. The difference in the mutually trans Ir -Cl bond lengths is ascribed to the inequivalence of intramolecular non-bonding interactions. The Ir -P(trans to PMe2Ph) bond length in (1) is shorter than that in mer -(PMe2Ph)Cl3IrIII. The smaller steric requirement of the hydride ligand in (1) allows the mutually trans phosphines to move away from their cis neighbour. In turn, the phosphines approach the metal more closely to compensate for the decreased phosphine substituent-phosphine substituent non-bonding interactions.

The crystal and molecular structure of 4-phosphonomethyl-2-oxo-1-piperazinylacetic acid

1989 ◽  
Vol 54 (1) ◽  
pp. 160-165 ◽  
Author(s):  
František Pavelčík ◽  
Karol Havetta ◽  
Jaroslav Páterek
Keyword(s):  
Molecular Structure ◽  
Double Bond ◽  
Single Crystals ◽  
Functional Group ◽  
Least Squares Method ◽  
Crystal And Molecular Structure ◽  
Monoclinic Space Group ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
X Ray

The structure of the title compound was determined by the method of X-ray diffraction of single crystals. The substance crystallizes in the P21/c monoclinic space group. The structure was refined by the least squares method to R = 0.044 on the basis of 2 076 observed reflections. It was found that this compound is not a dicarboxylic acid but rather an intramolecularly cyclized lactam. The hydrogen phosphonato functional group participates in the betain form, while the carboxyl group is not ionized. The conformation of the six-membered oxopiperazine ring is similar to that of cyclohexane in which the peptidic group plays a similar role to the double bond.

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