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.

scholarly journals Intermolecular hydrogen bonding in isostructural pincer complexes [OH-( t-BuPOCOP t-Bu)MCl] (M = Pd and Pt)

2019 ◽  
Vol 75 (7) ◽  
pp. 1011-1014
Author(s):  
Markus Joksch ◽  
Anke Spannenberg ◽  
Torsten Beweries
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Pincer Complexes ◽  
Intermolecular Hydrogen Bonding ◽  
Square Planar ◽  
Chloride Ligand ◽  
Halide Ligand ◽  
Hydrogen Bonded

In the crystal structure of the isostructural title compounds, namely {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridopalladium(II), [Pd(C22H39O3P2)Cl], 1, and {2,6-bis[(di-tert-butylphosphanyl)oxy]-4-hydroxyphenyl}chloridoplatinum(II), [Pt(C22H39O3P2)Cl], 2, the metal centres are coordinated in a distorted square-planar fashion by the POCOP pincer fragment and the chloride ligand. Both complexes form strong hydrogen-bonded chain structures through an interaction of the OH group in the 4-position of the aromatic POCOP backbone with the halide ligand.

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.

N,N′-methylenedipyridinium Pt(II) and Pt(IV) hybrid salts: synthesis, crystal and molecular structures of [(C5H5N)2CH2] · [PtCl4] and [(C5H5N)2CH2] · [PtCl6]

2012 ◽  
Vol 66 (11) ◽  
Author(s):  
Mahmoud Al-Ktaifani ◽  
Mwaffak Rukiah
Keyword(s):  
Crystal Structure ◽  
Molecular Structures ◽  
Planar Geometry ◽  
X Ray Diffraction ◽  
Inorganic Hybrid ◽  
X Ray ◽  
Crystal And Molecular Structures ◽  
Square Planar ◽  
Ionic Compounds ◽  
Methylene Group

AbstractThe highly insoluble organic-inorganic hybrid ionic compounds N,N′-methylenedipyridinium tetrachloroplatinate(II) [(C5H5N)2CH2] · [PtCl4] and N,N′-methylenedipyridinium hexachloroplatinate(IV) [(C5H5N)2CH2] · [PtCl6] were obtained by the treatment of N,N′-methylenedipyridinium dichloride monohydrate [(C5H5N)2CH2]Cl2 · H2O with K2[PtCl4] or (NH4)2[PtCl6], respectively, in an aqueous solution. Both complexes were isolated, purified, characterised by elemental analysis, and their molecular structures were confirmed by powder X-ray diffraction. The crystal structure of both compounds consists of separated discrete dications [(C5H5N)2CH2]2+ and anions [PtCln]2− (n = 4 or 6). As anticipated, the dications formed a butterfly shape consisting of two pyridine rings bound to the methylene group via their N atoms, while the Pt centre had a square planar geometry in [(C5H5N)2CH2] · [PtCl4] and an octahedral coordination in [(C5H5N)2CH2] · [PtCl6]. Interestingly, both crystal structures are stabilised by intermolecular C-H…Cl non-standard hydrogen bonds, π-π ring interactions between two pyridine rings of adjacent dications, and also by Cl-π interactions.

Steric Modification of M-P Bond Lengths: Crystal and Molecular-Structures of the Platinum(II) Complexes trans-(PPrI3)2ClnH2-nPtII (N = 0-2)

1986 ◽  
Vol 39 (10) ◽  
pp. 1495 ◽  
Author(s):  
GB Robertson ◽  
PA Tucker ◽  
WA Wickramasinghe
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Room Temperature ◽  
Platinum Complexes ◽  
Molecular Structures ◽  
Crystal And Molecular Structures ◽  
Anionic Ligand ◽  
Trans Bond ◽  
Square Planar ◽  
Ligand Conformation

Crystal structure analyses of the square-planar platinum complexes trans-(PPri3)2ClnH2-nPtII(n = 0-2) (C), (B), (A) are described. Diffraction data were recorded at room temperature with a Picker FACS-1 diffractometer. Convergence R values, for reflection numbers given in parentheses, are 0.020 (2373), (A), 0.021 (5771), (B) and 0.018 (1982), (C). The ligand conformation about the Pt-P bonds is perpendicular for (A) and (B) and eclipsed for (C). The Pt-P distances decrease systematically with increasing hydride content [2.339(1)Ǻ, (A); 2.286(1)Ǻ, (B); 2.252(1)Ǻ, (C)]. The decrease reflects the low steric requirement of hydride vis a vis chloride ligands and concomitant changes in anionic ligand/phosphine substituent non-bonding interactions. The trans-bond lengthening of the Pt- Cl bond in (B)(due to trans hydride) is 0.092(1)Ǻ.

Synthesis and crystal structure analyses of tri-substituted guanidine-based copper(II) complexes

2021 ◽  
Vol 76 (3-4) ◽  
pp. 193-199
Author(s):  
Muhammad Said ◽  
Sadia Rehman ◽  
Muhammad Ikram ◽  
Hizbullah Khan ◽  
Carola Schulzke
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Molecular Structures ◽  
Hydroxyl Groups ◽  
Synthesis And Crystal Structure ◽  
Pyramidal Geometry ◽  
Tautomeric Forms ◽  
Square Planar ◽  
Nitrogen Donor ◽  
Square Pyramidal Geometry

Abstract Three guanidine-derived tri-substituted ligands viz. N-pivaloyl-N′,N″-bis-(2-methoxyphenyl)guanidine (L1), N-pivaloyl-N′-(2-methoxyphenyl)-N″-phenylguanidine (L2) and N-pivaloyl-N′-(2-methoxyphenyl)-N″-(2-tolyl)guanidine (L3) were reacted with Cu(II) acetate to produce the corresponding complexes. The significance of the substituent on N″ for the resulting molecular structures and their packing in the solid state has been studied with respect to the structural specifics of the corresponding Cu(II) complexes. The key characteristic of the guanidine-based metal complexation with Cu(II) is the formation of an essentially square planar core with an N2O2 donor set. As an exception, in the complex of L1, the substituent’s methoxy moiety also interacts with the Cu(II) center to generate a square-pyramidal geometry. The hydroxyl groups of the imidic acid tautomeric forms of L1–L3, in addition to N″, are also bonded to Cu(II) in all three complexes rather than the nitrogen donor of the guanidine motif.

The molecular and crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

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