Infrared and crystal structure study of .sigma. vs. .pi. bonding in tetrahedral zinc(II) complexes. Crystal and molecular structures of dichlorobis(4-substituted pyridine)zinc(II) complexes

1977 ◽  
Vol 16 (5) ◽  
pp. 1119-1127 ◽  
Author(s):  
W. L. Steffen ◽  
Gus J. Palenik
Keyword(s):  
Crystal Structure ◽  
Structure Study ◽  
Molecular Structures ◽  
Crystal And Molecular Structures

Untersuchungen an Stickstoff-Brom-Verbindungen, IV / Studies on Nitrogen-Bromine Compounds, IV

1977 ◽  
Vol 32 (12) ◽  
pp. 1416-1420 ◽  
Author(s):  
Omar Jabay ◽  
Hans Pritzkow ◽  
Jochen Jander
Keyword(s):  
Crystal Structure ◽  
Nitrogen Atom ◽  
Structure Analysis ◽  
Electron Acceptors ◽  
Molecular Structures ◽  
Hydrogen Atoms ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Solid Nitrogen ◽  
Intermolecular Contacts

The crystal and molecular structures of N-bromobenzamide (NBB), N-bromosuccinimide (NBS), and N,N-dibromobenzenesulfonamide (NBBS) were determined by X-ray structure analysis. The nitrogen atoms in NBB and NBS have a trigonal planar coordination (sp2) and the N—Br distances lie in the same range (1.82 A, 1.84 A). The N—Br distance in NBBS, where the nitrogen atom is sp3-hybridized, is somewhat longer (1.88 A). In these structures the molecules are connected by O···H—N (NBB), O···Br—N (NBS) or N···Br—N (NBBS) intermolecular bonds forming endless chains; positivated hydrogen atoms or, in case that they are absent, positivated bromine atoms act as electron acceptors with oxygen or sp3- hybridized nitrogen atoms. These results suggest, that in solid nitrogen tribromide, the crystal structure of which cannot be determined, the nitrogen atoms will be sp3-hybridized and intermolecular contacts via N—Br···N will occur.

scholarly journals Preparation and Crystal Structure of a Platinum(II) Complex of [CH2N(CH2COOH)CH2CONH2]2, the Hydrolysis Product of an Anti-Tumour Bis(3,5-Dioxopiperazin-1-YL)Alkane

1994 ◽  
Vol 1 (4) ◽  
pp. 321-328 ◽  
Author(s):  
Kevin B. Nolan ◽  
Leo P. Ryan ◽  
Colm J. Campbell ◽  
Patrick McArdle ◽  
Desmond Cunningham ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrolysis Product ◽  
Molecular Structures ◽  
3 Dimensional ◽  
Crystal And Molecular Structures ◽  
Dimensional Network ◽  
Square Planar ◽  
Ligand Bond ◽  
Hydrogen Bonded

The synthesis and crystal and molecular structures of the platinum(II) complex Pt(HL)Cl where H2L is the diacid diamide –[CH2N(CH2COOH)CH2CONH2]2, a hydrolytic metabolite of an antitumour active bis(3,5-dioxopiperazin-1-yl)alkane are reported. The complex is square planar and contains HL− as a tridentate 2N (amino), O (carboxylate) donor. The metal to ligand bond distances are Pt-Cl 2.287(1) Å, Pt-O 2.002 (1) Å, Pt-Ntrans Cl 2.014(1) Å and Pt-Ntrans O 2.073 Å. There is extensive hydrogen bonding, each molecule of Pt(HL)Cl being intermolecularly hydrogen bonded to ten others giving a 3-dimensional network. There is also one intramolecular H-bond.

Purine complexes of platinum: synthesis, nmr, and crystal and molecular structures of cis-chloro(caffeine)bis(triethylphosphine)platinum(II) fluoroborate and cis-bis(isocaffeine)bis(triethylphosphine)platinum (II) fluoroborate

1983 ◽  
Vol 61 (6) ◽  
pp. 1132-1141 ◽  
Author(s):  
Gordon William Bushnell ◽  
Roderick James Densmore ◽  
Keith Roger Dixon ◽  
Arthur Charles Ralfs
Keyword(s):  
Crystal Structure ◽  
Nmr Spectra ◽  
Molecular Structures ◽  
Platinum Drugs ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Bond Lengths ◽  
Antitumour Agents ◽  
Crystal And Molecular Structures ◽  
Square Planar

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.

Arsenic(III), Antimony (III) and Bismuth(III) Thiobenzoates: Crystal and Molecular Structures of M(SOCR)3 and PhSb(SOCPh)2

1998 ◽  
Vol 53 (12) ◽  
pp. 1475-1482 ◽  
Author(s):  
Prit Singh ◽  
Sudha Singh ◽  
Vishnu D. Gupta ◽  
Heinrich Nöth
Keyword(s):  
Crystal Structure ◽  
Molecular Structures ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Covalently Bonded ◽  
Bismuth Complex ◽  
Group 15 ◽  
Structure Determinations ◽  
Trigonal Pyramid ◽  
Trigonal Prisms

Abstract Tris-thiobenzoates, Arsenic, Antimony, Bismuth Tris-thiobenzoates of arsenic, antimony and bismuth, M(SOCR)3 have been obtained from their oxides and characterized. In the X-ray crystal structure determinations of these, the group 15 atom and the three covalently bonded sulfur atoms are found to constitute a trigonal pyramid, the central atoms lie at a C3 axis. In the bismuth complex the thiobenzoate ligand tends to chelate. However, three comparatively short intermolecular M···S interactions are significant features for these molecules resulting in stacking of trigonal prisms providing an essentially six coordinate environment around arsenic and antimony and a nine-coordinate one for bismuth. The structure of PhSb(SOCPh)2 can be considered

The First Molecular Complex Containing Two Azoarenes. The Crystal Structure of Decafluoroazobenzene/Azomesitylene (1 : 1)

1989 ◽  
Vol 42 (5) ◽  
pp. 741 ◽  
Author(s):  
MI Bruce ◽  
ERT Tiekink
Keyword(s):  
Crystal Structure ◽  
Molecular Complex ◽  
Title Compound ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Vertical Separation ◽  
Full Matrix ◽  
Crystal And Molecular Structures ◽  
Cell Dimensions ◽  
Unit Cell Dimensions

The crystal and molecular structures of the title compound, C12F10N2.C18H22H2,are reported. The crystal structure is comprised of stacks of alternate decafluoroazobenzene and azomesitylene molecules with the vertical separation between successive molecules being approximately 3.42 � . The stacks are aligned so that the azobenzene molecules of one stack are adjacent to the azomesitylene molecules of the neighbouring stacks; there are no significant intercolumn contacts. Crystals are monoclinic, space group P21/n with unit cell dimensions a 7.197(2), b 15.432(3), c 12.513(3) � , β 96.33(2)� , and Z 2. The structure was refined by a full-matrix least-squares procedure to final R 0.059 for 915 reflections for which 1 ≥ 3.O σ(I).

scholarly journals (N,N-Diisopropyldithiocarbamato)triphenyltin(IV): crystal structure, Hirshfeld surface analysis and computational study

2019 ◽  
Vol 75 (10) ◽  
pp. 1479-1485 ◽  
Author(s):  
Farah Natasha Haezam ◽  
Normah Awang ◽  
Nurul Farahana Kamaludin ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink
Keyword(s):  
Crystal Structure ◽  
Surface Analysis ◽  
Computational Study ◽  
Close Approach ◽  
Molecular Geometry ◽  
Hirshfeld Surface ◽  
Molecular Structures ◽  
Crystal And Molecular Structures ◽  
Dithiocarbamate Ligand ◽  
Dimeric Aggregates

The crystal and molecular structures of the title triorganotin dithiocarbamate, [Sn(C6H5)3(C7H14NS2)], are described. The molecular geometry about the metal atom is highly distorted being based on a C3S tetrahedron as the dithiocarbamate ligand is asymmetrically chelating to the tin centre. The close approach of the second thione-S atom [Sn...S = 2.9264 (4) Å] is largely responsible for the distortion. The molecular packing is almost devoid of directional interactions with only weak phenyl-C—H...C(phenyl) interactions, leading to centrosymmetric dimeric aggregates, being noted. An analysis of the calculated Hirshfeld surface points to the significance of H...H contacts, which contribute 66.6% of all contacts to the surface, with C...H/H...C [26.8%] and S...H/H...H [6.6%] contacts making up the balance.

scholarly journals Crystal and molecular structures of some phosphane-substituted cymantrenes [(C5H4 X)Mn(CO)LL′] (X = H or Cl, L = CO, L′ = PPh3 or PCy3, and LL' = Ph2PCH2CH2PPh2)

2021 ◽  
Vol 77 (10) ◽  
Author(s):  
Karlheinz Sünkel ◽  
Christian Klein-Hessling
Keyword(s):  
Crystal Structure ◽  
Uv Irradiation ◽  
Molecular Structures ◽  
Bond Lengths ◽  
Crystal And Molecular Structures ◽  
Chlorine Substitution ◽  
Small Influence ◽  
Intermolecular Association ◽  
Structure Determinations

UV irradiation of tetrahydrofuran solutions of [CpMn(CO)3] (Cp = π-C5H5 or π-C5H4Cl) in the presence of the phosphanes PPh3 or PCy3 (Cy = cyclohexyl) and Ph2PCH2CH2PPh2 yields the substitution products [CpMn(CO)2PR 3] (R = Ph or Cy) and [CpMn(CO)(Ph2PCH2CH2PPh2)], namely, dicarbonyl(η5-cyclopentadienyl)(triphenylphosphane-κP)manganese(I), [Mn(C5H5)(C18H15P)(CO)2], 1a, dicarbonyl(η5-1-chlorocyclopentadienyl)(triphenylphosphane-κP)manganese(I), [Mn(C5H4Cl)(C18H15P)(CO)2], 1b, dicarbonyl(η5-cyclopentadienyl)(tricyclohexylphosphane-κP)manganese(I), [Mn(C5H5)(C18H33P)(CO)2], 2a, dicarbonyl(η5-1-chlorocyclopentadienyl)(tricyclohexylphosphane-κP)manganese(I), [Mn(C5H4Cl)(C18H33P)(CO)2], 2b, carbonyl(η5-cyclopentadienyl)[1,2-bis(diphenylphosphanyl)ethane-κ2 P,P′]manganese(I), [Mn(C5H5)(C26H24P2)(CO)], 3a, and carbonyl(η5-1-chlorocyclopentadienyl)[1,2-bis(diphenylphosphanyl)ethane-κ2 P,P′]manganese(I), [Mn(C5H4Cl)(C26H24P2)(CO)], 3b, The crystal structure determinations show a very small influence of the chlorine substitution and a moderate influence of the phosphane substitution on the bond lengths. The PR 3 groups avoid being eclipsed with the C—Cl bonds. All the compounds employ weak C—H...O interactions for intermolecular association, which are enhanced by C—H...Cl contacts in the chlorinated products.

scholarly journals Structural Characterization of Two Polymorphs of 1-(4-Methylpyridin-2-yl)thiourea and Two Derived 2-Aminothiazoles

2020 ◽  
Author(s):  
Denise Böck ◽  
Andreas Beuchel ◽  
Richard Goddard ◽  
Peter Imming ◽  
Rüdiger W. Seidel
Keyword(s):  
Crystal Structure ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Hantzsch Reaction ◽  
Orthorhombic Space Group ◽  
Monoclinic System ◽  
Space Group ◽  
Crystal And Molecular Structures ◽  
Polymorphic Forms ◽  
Hydrogen Bonded

Abstract Two polymorphic forms of 1-(4-methylpyridin-2-yl)thiourea (1) and the crystal and molecular structures of the 2-aminothiazoles N-(4-methylpyridin-2-yl)-4-(pyridin-2-yl)thiazol-2-amine (2) and N-(4-methylpyridin-2-yl)-4-(pyrazin-2-yl)thiazol-2-amine (3), derived from 1 and the respective α-bromoketone via the Hantzsch reaction, are described. Both polymorphic forms 1α (space group P21/c, Z = 4) and 1β (space group P21/n, Z = 8) crystallize in the monoclinic system but exhibit distinctly different intermolecular hydrogen bonding patterns. Compound 2 (orthorhombic, space group Pca21, Z = 8) forms polymeric N–H⋯N hydrogen-bonded zigzag tapes in the polar crystal structure, with a significant twisting between the thiazole and pyridine rings. In contrast, the crystal structure of 3 (monoclinic, space group P21/c, Z = 4) features nearly planar centrosymmetric N–H⋯N hydrogen-bonded dimers, which are laterally joined through long C–H⋯N contacts, affording a π⋯π stacked layered structure. Graphic Abstract Two polymorphs of 1-(4-methylpyridin-2-yl)thiourea and the crystal and molecular structures of two 2-aminothiazoles, derived from 1-(4-methylpyridin-2-yl)thiourea and α-bromoketones via Hantzsch reaction, are reported.

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