scholarly journals 4-METHYL HYPPURIC ACID: A CASE OF POLYMORPHISM AND SOLVATOMORPHISM

2019 ◽  
Vol 16 (32) ◽  
pp. 812-819
Author(s):  
G. DELGADO ◽  
M. GUILLEN ◽  
A. J. MORA
Keyword(s):  
Pharmaceutical Industry ◽  
Physical Properties ◽  
Crystal Packing ◽  
Solid Material ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
Pharmaceutical Ingredients ◽  
Orthorhombic Cell

Polymorphism is known as the ability of a solid material to exist in more than one form or crystal structure, with important applications in the preparation of active pharmaceutical ingredients. Characterization of different polymorphs of the specific metabolite of 4-xylene can contribute to the chemical and pharmaceutical industry. Polymorphism is of particular importance in industrial processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a manufactured product. This is particularly so for the design and production of drugs in the pharmaceutical industry, as varying physical properties between different polymorphs can affect shelf life and durability, solubility, as well as bioavailability and manufacturing of the drug. The crystallization, spectroscopic and X-ray diffraction characterization of two polymorph and one solvatomorph of 4-methylhippuric acid are presented. These compounds crystallizes in different crystalline systems. Polymorph I (4mH-I) crystalize in an orthorhombic cell with space group P212121. Polymorph II (4mHII) crystallizes in a monoclinic space group P21/c. Solvatomorph (4mH-S) crystallizes in a triclinic P-1 cell. All polymorphs crystallize in neutral form. The crystal packing of the three compounds are governed by hydrogen bonds intermolecular interactions of the type N--H···O and O--H···O forming tridimensional networks.

scholarly journals Serendipitous formation and characterization of K2[Pd(NO3)4]·2HNO3

2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
Glass Ampoule ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.

Polysulfonylamine, XCVII [1] Di(organosulfonyl)amine und ihre konjugierten Anionen als simultane Baugruppen in zwei supramolekularen Strukturen / Polysulfonylamines, XCVII [1] Di(organosulfonyl)amines and their Conjugate Anions as Simultaneous Building Blocks in Two Supramolecular Structures

1997 ◽  
Vol 52 (10) ◽  
pp. 1229-1236 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Crystal Packing ◽  
Building Blocks ◽  
Complex Compounds ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
Diffraction Structure ◽  
Bond System ◽  
Bond Network ◽  
Anion Interaction

The complex compounds 4HN (SO2Me)2 · (diaza-18-crown-6) (1) and Na[N(SO2Ph)2] · 2HN(SO2Ph)2 · 2 (12-crown-4) · 2 MeOH (2) were obtained from their components and characterized by low-temperature X-ray diffraction. Structure 1 (monoclinic, space group P21/n) displays centrosymmetric formula units consisting of a biangular diazonia-18-crown-6 dication, two (MeSO2)2N− anions situated above and below the macrocycle and linked to the NH2+ groups via an N - H ··· O and N -H ··· N bond system, and finally two HN(SO2Me)2 molecules, each forming an N -H ··· O bond to one of the anions. The molecule-anion entity represents an iso form of the [(RSO2)2N -H ··· N (SO2R)2]− homoconjugates previously described. The crystal packing of 1 is stabilized by an extensive and highly organized [H2C -H ··· O(S)] hydrogen bond network. Structure 2 (monoclinic, space group P21/n) exhibits inconspicuous [Na(12-crown-4)2]+ cations and, as a striking feature, supramolecular anions assembled from a central (PhSO2)2N− ion, two MeOH molecules flanking the amide anion, and two HN (SO2Ph)2 molecules bonded to the MeOH moieties. The assembly is held together by two N -H ··· O(H )(Me) bonds, one MeO -H ··· N− bond and one MeO -H ··· O(anion) interaction. For both structures, conformational peculiarities of the N(SO2C)2 groups are discussed.

Synthesis and structural characterization of donor-stabilized disubstituted diphenyldithiophosphates of nickel(II)

2014 ◽  
Vol 70 (4) ◽  
pp. 761-767 ◽  
Author(s):  
Sandeep Kumar ◽  
Ruchi Khajuria ◽  
Amanpreet Kaur Jassal ◽  
Geeta Hundal ◽  
Maninder S. Hundal ◽  
...  
Keyword(s):  
Single Crystal ◽  
Chelate Ring ◽  
Donor Ligands ◽  
Monoclinic Space Group ◽  
Bidentate Ligands ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray

Donor-stabilized addition complexes of nickel(II) with disubstituted diphenyldithiophosphates, [{(ArO)2PS2}2NiL2] {Ar = 2,4-(CH3)2C6H3[(1), (5)], 2,5-(CH3)2C6H3[(2), (6)], 3,4-(CH3)2C6H3[(3), (7)] and 3,5-(CH3)2C6H3[(4), (8)];L= C5H5N [(1)–(4)] and C7H9N [(5)–(8)]}, were successfully isolated and characterized by elemental analysis, magnetic moment, IR spectroscopy and single-crystal X-ray analysis. Compound (4) crystallizes in the monoclinic space groupP21/nwhereas compounds (7) and (8) crystallize in the triclinic space group P\bar 1. The single-crystal X-ray diffraction analysis of (4), (7) and (8) reveals a six-coordinated octahedral geometry for the NiS4N2chromophore. Two diphenyldithiophosphate ions act as bidentate ligands with their S atoms coordinated to the Ni centre. Each of them forms a four-membered chelate ring in the equatorial plane. The N atoms from two donor ligands are axially coordinated to the Ni atom.

Steric Modification of Metal-Phosphorus Bond Lengths: the Preparation, Characterization and CrystalStructures of mer-trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII

1995 ◽  
Vol 48 (6) ◽  
pp. 1183 ◽  
Author(s):  
EJ Ditzel ◽  
GB Robertson
Keyword(s):  
Chloride Content ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
Steric Crowding ◽  
Unit Increase

The syntheses and subsequent characterization of the complexes mer -trans-(PPri3)2(Pme2Ph)-Cl-cis-H2IrIII(1) and mer-trans-(PPri3)2(PMe2Ph)H3IrIII (2) by n.m.r. and by low temperature (153�5 K) X-ray diffraction analyses are reported. Crystals of (1) are monoclinic, space group P21/c with a 19.277(2), b 9.020(1), c 17.657(2) Ǻ, β 101.40(1)° and Z 4. Crystals of (2) are orthorhombic, space group P212121, with a 19.373(3), b 18.724(2), c 8.113(1) Ǻ and Z 4. Full-matrix least-squares analyses converged with R = 0.027 and wR = 0.031 for (1) (3243 reflections), and R = 0.030 and wR = 0.038 for (2) (2892 reflections). Consistent with previous observation, the unit increase in chloride content (in place of hydride) in (1) is accompanied by a global lengthening of 0.036 Ǻ (av.) in the Ir -P bond lengths cf. those in (2). Also, because of increased steric crowding (two PPri3 ligands in place of two Pme2Ph), the Ir-PMe2Ph bond in (1) is 0.019(2) Ǻ longer than the chemically equivalent bond in mer-(PMe2Ph)3Cl-cis-H2IrIII. In previously reported complexes in this series metrically similar increases in Ir-PMe2Ph distances result from the replacement of just one Pme2Ph ligand by PPri3.

scholarly journals Efficient Synthesis and X-ray Structure of [1,2,4]Triazolo[4,3-a]pyriaadines via Oxidative Cyclization Using N-Chlorosuccinimide (NCS)

Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1156
Author(s):  
Said El-Kurdi ◽  
Bassam Abu Thaher ◽  
Kanan Wahedy ◽  
Dieter Schollmeyer ◽  
Levin Nopper ◽  
...  
Keyword(s):  
Biological Activity ◽  
Oxidative Cyclization ◽  
Monoclinic Space Group ◽  
Efficient Synthesis ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Mild Conditions ◽  
Pharmaceutical Applications

Triazolopyridines are a family of compounds that, owing to their biological activity, have many pharmaceutical applications. In this study, 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine and 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine were synthesized by using the chlorinated agent NCS for hydrazones under very mild conditions. The characterization of these compounds was achieved by 1H NMR, 13C NMR, FTIR, MS and X-ray diffraction. The compound 3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 15.1413(12), b = 6.9179(4), c = 13.0938(8) Å, β = 105.102(6)°, V = 1324.16(16)Å3, Z = 4, and R = 0.0337. Also compound 6-bromo-3-(pyridine-4-yl)-[1,2,4]triazolo[4,3-a]pyridine was crystallized in the monoclinic space group P 21/c with a = 14.3213(11), b = 6.9452(4) (4), c = 12.6860(8)Å, β = 100.265(6)°, V = 1241.62(14)Å3, Z = 4, and R = 0.0561.

Darstellung und spektroskopische Charakterisierung von Methylnitro-closo-hexaboraten sowie Kristallstrukturen von cis-(Ph4As)2[B6H4(CH3)(NO2)],fac-(Ph4As)2[B6H3(CH3)(NO2)2] · CH3CN und mer-(Ph4P)2[B6H3(CH3)(NO2)C2] / Synthesis and Spectroscopic Characterization of Methylnitro-closo-hexaborates and Crystal Structures of cis -(Ph4As)2[B6H4(CH3)(NO2)],fac-(Ph4As)2[B6H3(CH3)(NO2)2] · CH3CN and mer-(Ph4P)2[B6H3(CH3)(NO2)C2]

1999 ◽  
Vol 54 (3) ◽  
pp. 349-356 ◽  
Author(s):  
C. Drewes ◽  
W. Preetz
Keyword(s):  
Nmr Spectra ◽  
Spectroscopic Characterization ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Dichloromethane Solution ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cis And Trans

By electrochemical oxidation of (n-Bu4N)[B6H6(CH3)] in the presence of nitrite ions and of the base DBU in dichloromethane solution cis- and trans-[B6H4(CH3)(NO2)]2- , fac- [B6H3(CH3)(NO2)2]2- and mer-[B6H3(CH3)(NO2)c2]2- are formed. X-ray diffraction analyses have been performed on single crystals of cis-(Ph4As)2[B6H4(CH3O)(NO2)] (1) (monoclinic, space group P21/a, a = 20.063(2), b = 10.858(1), c =21.384(2) Å, β = 105.818(9)°, Z = 4), fac-(Ph4As)2[B6H3(CH3)(NO2)2] ·CH3CN (2) (triclinic, space group P1̄, a = 10.333(3), b = 10.695(3), c = 22.833(6) Å, α = 93.91(3), β = 96.79(3), γ = 104.56(2)°, Z = 2), and mer-(Ph4P)2[B6H3(CH3)(NO2)c2] (3) (triclinic, space group P1̄, a - 10.100(1), b = 10.402(3), c = 22.923(3) Å, α = 96.328(18), β = 89.928(12), γ = 107.963(16)°, Z = 2). The 11B NMR spectra and the vibrational spectra of the methylnitro compounds are discussed and compared with those of the monomethyl- and mononitro-closo-hexaborates.

Isobaric and isochoric freezing of CH2BrCl and isostructural relations between CH2Cl2, CH2Br2 and CH2BrCl

2007 ◽  
Vol 63 (6) ◽  
pp. 903-911 ◽  
Author(s):  
Marcin Podsiadło ◽  
Andrzej Katrusiak
Keyword(s):  
High Pressures ◽  
Crystal Packing ◽  
Ambient Pressure ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Potential Surfaces ◽  
Space Group ◽  
Cl Atoms

Bromochloromethane, CH2BrCl, has been temperature-frozen and in situ pressure-frozen and the structure determined by X-ray diffraction at low temperatures of 170 and 100 K at ambient pressure (0.10 MPa), and at high pressures of 1.04 and 1.72 GPa at room temperature (295 K). CH2BrCl exhibits a remarkable polymorphism: at low temperature it crystallizes in the monoclinic space group C2/c (phase I), isostructural to the crystals of CH2Br2. The pressure-frozen crystal of CH2BrCl is orthorhombic, space group Pbcn, and is isostructural to the crystal of CH2Cl2. In both phases I and II the Br and Cl atoms are substitutionally disordered. The freezing temperatures and pressures of simple dihalomethanes have been correlated to their molecular weight and halogen... ˙˙halogen distances. Calculated electrostatic potential surfaces have been related to the different crystal packing of dihalomethanes investigated.

Lewis-Base Adducts of Group 11 Metal(I) Compounds. LII. Synthesis and Structural Characterization of Mononuclear Chloro- and Bromo-pyridinebis-(triphenylphosphine)silver(I) Complexes

1989 ◽  
Vol 42 (6) ◽  
pp. 907 ◽  
Author(s):  
LM Engelhardt ◽  
PC Healy ◽  
JD Kildea ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structural Characterization ◽  
Silver Atom ◽  
Lewis Base ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
Weak Coordination

The mononuclear adducts chloro - and bromo-pyridinebis (triphenylphosphine)silver have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. The two complexes are isomorphous, monoclinic, space group P21 or P21/m, a ≈ 9.8, b ≈ 20.0, c ≈ 9.1 � , β ≈ 97.5�, Z 2; in space group P21/m, they were refined to residuals of 0.038, 0.036 for 2392, 2157 'observed' reflections respectively. No comparable iodide adduct has been isolated. In both structures the silver atom is four-coordinate; Ag-Cl,Br are 2.511(2), 2.629(1) �; Ag-P, 2.472(1), 2.476(1) �, and Ag-N, 2.585(5), 2.570(5) � respectively, the Ag-N distance being longer than Ag-P, indicating very weak coordination of the pyridine.

scholarly journals Synthesis and characterization of Ti(IV), Zr(IV) and Al(III) salen-based complexes

2021 ◽  
Vol 12 (2) ◽  
pp. 216-221
Author(s):  
Joana Hipolito ◽  
Luis Alves ◽  
Ana Martins
Keyword(s):  
Solid State ◽  
Molecular Structures ◽  
Monoclinic Space Group ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Tetrahedral Geometry ◽  
Triclinic Space Group ◽  
Space Group ◽  
High Yields

New Ti(IV), Zr(IV) and Al(III) salen-based complexes of formulae [(L)TiCl2], 2, [(L)ZrCl2], 3, and [(L){Al(CH2CH(CH3)2)2}2], 4, where L = meso-(R,S)-diphenylethylene-salen, were synthesized in high yields. [(L){Al(CH2CH(CH3)2)2}2] is a bimetallic complex that results from the reaction of H2L with either 1 or 2 equivalent of Al(CH2CH(CH3)2)3. The solid-state molecular structures of compounds 2 and 4·(C7H8) were obtained by single-crystal X-ray diffraction. Crystal data for C44H54Cl2N2O2Ti, (2a): monoclinic, space group C2/c (no. 15), a = 27.384(1) Å, b = 12.1436(8) Å, c = 28.773(2) Å, β = 112.644(2)°, V = 8830.6(9) Å3, Z = 8, μ(MoKα) = 0.350 mm-1, Dcalc = 1.146 g/cm3, 26647 reflections measured (5.204° ≤ 2Θ ≤ 50.7°), 8072 unique (Rint = 0.0967, Rsigma = 0.1241) which were used in all calculations. The final R1 was 0.0640 (I > 2σ(I)) and wR2 was 0.1907 (all data). Crystal data for C62H72Cl2N2O2Ti (2b): monoclinic, space group P21/c (no. 14), a = 19.606(1) Å, b = 12.793(1) Å, c = 23.189(2) Å, β = 105.710(4)°, V = 5599.0(7) Å3, Z = 4, μ(MoKα) = 0.291 mm-1, Dcalc = 1.182 g/cm3, 37593 reflections measured (3.65° ≤ 2Θ ≤ 50.928°), 10304 unique (Rint = 0.0866, Rsigma = 0.1032) which were used in all calculations. The final R1 was 0.0593 (I > 2σ(I)) and wR2 was 0.1501 (all data). Crystal data for C67H97Al2N2O2 (4·(C7H8)): triclinic, space group P-1 (no. 2), a = 10.0619(9) Å, b = 16.612(2) Å, c = 21.308(2) Å, α = 67.193(5)°, β = 78.157(6)°, γ = 77.576(5)°, V = 3176.8(6) Å3, Z = 2, μ(MoKα) = 0.088 mm-1, Dcalc = 1.063 g/cm3, 42107 reflections measured (5.382° ≤ 2Θ ≤ 51.624°), 12111 unique (Rint = 0.0624, Rsigma = 0.0706) which were used in all calculations. The final R1 was 0.0568 (I > 2σ(I)) and wR2 was 0.1611 (all data). The solid-state molecular structure of [(L){Al(CH2CH(CH3)2)2}2] reveals that both metal centres display a slightly distorted tetrahedral geometry bridged by the salen ligand. Both [(L)TiCl2] and [(L)ZrCl2] complexes display octahedral geometry with trans-chlorido ligands.

Synthesis and Characterization of Silver(I) Saccharinate Complexes with Pyrazole and Imidazole Ligands: [Ag(sac)(pz)(H2O)]n and [Ag(sac)(im)] · 2H2O

2006 ◽  
Vol 61 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Veysel T. Yilmaz ◽  
Sevim Hamamci ◽  
Orhan Büyükgüngör
Keyword(s):  
Hydrogen Bonds ◽  
Three Dimensional ◽  
Helical Chain ◽  
Supramolecular Network ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
Space Group ◽  
Square Planar

AbstractTwo new silver(I) saccharinate (sac) complexes, [Ag(sac)(pz)(H2O)]n (1) and [Ag(sac)(im)]·2H2O (2) (pz = pyrazole and im = imidazole), have been prepared and characterized by elemental analysis, IR spectroscopy, thermal analysis and single crystal X-ray diffraction. Complexes 1 and 2 crystallize in the monoclinic space group P21/c and triclinic space group P1̅, respectively. The sac, pz and im ligands all are N-coordinated. In 1, the [Ag(sac)(pz)] units are bridged by aqua ligands to generate a one-dimensional helical chain, in which the silver(I) ions exhibit a distorted square-planar AgN2O2 coordination geometry. The polymeric chains are connected by N-H· · ·O hydrogen bonds into sheets, which are further linked by aromatic π(pz) · · ·π(sac) stacking interactions into a three-dimensional supramolecular network. Complex 2 consists of individual molecules containing linearly coordinated silver(I) ions with a slightly distorted coordination of AgN2. The molecules interact with each other through hydrogen bonds and π· · ·π interactions to form a three-dimensional supramolecular network.

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