Recurrent motifs in pharmaceutical cocrystals involving glycolic acid: X-ray characterization, Hirshfeld surface analysis and DFT calculations

Crystallization studies on some pyridinecarboxamides and methylated xanthines with glycolic acid as coformer, were carried out on formation of synthons and their influence on stability and solubility, the energy landscape and stabilization energies.

Electrochemical Synthesis of N-Oxopyridine-2-thionate Complexes of Cd(II): The Crystal Structure of Bis(2,2′-bipyridine)(N-oxopyridine-2-thionate) Cadmium(II) Perchlorate 1/4 (Bipyridine)

The electrochemical oxidation of Cd in acetonitrile solution of 1-hydroxy-2-pyridinethione (HPT) and 2,2′-bipyridine (bipy) affords [Cd(PT)2(bipy)] · H2O and [Cd(PT)(bipy)2]ClO4· 1/4(bipy). The crystal structure of the perchlorate salt shows the molecule to have a distorted octahedral CdN4OS skeleton.

Electrochemical Syntheses of Pyrimidine-2-thiolato Complexes of Nickel(II) / Crystal and Molecular Structure of 2,2′-Bipyridine-bis(pyrimidine-2-thiolato)nickel(II) Monohydrate

The electrochemical oxidation of nickel in pyrimidine-2-thione (pymt H) solution yields a compound of formula [Ni(pymt)2]. When pyridine (py), 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) are added to the solution phase, the product obtained is a complex [Ni(pymt)2py2] or [Ni(pymt)2L] (L = bipy or phen). The crystal structure of [Ni(pymt)2bipy] · H2O is monoclinic, space group P 21/c, with a = 726.6(2), b = 1586.2(2), c = 1696.7(4) pm, β = 99.04(4)° and Z = 4. The nickel atom has highly distorted octahedral coordination and the pyrimidine-2-thiolato ligand is bidentate, forming two four-membered chelate rings with a small “bite” angle of ca. 68°. The two sulphur atoms are in a trans arrangement. The vibrational and electronic spectra of the compounds are discussed.

Synthesis, Spectroscopic Characterization and Crystal and Molecular Structures of {Ph4P[(Se04 )(SnPh3 )(SnPh3X)]}n (X = Cl, Br)

The reactions of bis[triphenyltin(IV)] selenate monohydrate [(Ph3Sn)2O4Se · H2O ] with tetraphenylphosphonium halides Ph4PX (X = Cl, Br) led to the formation of 1:1 complexes of formula {Ph4P[(SeO4)(SnPh3 (SnPh3X)]k [X = Br (I) or Cl (II)], which were characterized by infrared, Mössbauer and H, 13C and Sn 119Sn NMR techniques and by X-ray diffractometry. The complexes have polymeric structures in which the [SnPh3]+ units alternate with bridging [SeO4]2- units, each of which also bears an SnPh3X side chain. In both the [SnPh3]+ and the [SnPh3X] units the coordination polyhedron of the tin atom is a distorted trigonal bipyramid.

The Crystal Structure of TlBrI2(4-methylpyridine-N-oxide)2

The unit cell of TlBrI2 (4-methylpyridine-N-oxide) 2 is orthorhombic, space group Pnna. with a = 1126.9(3),b = 919.8(2),c = 1210.4(3) pm.and Z = 4. The structure consists of discrete TlBrI2 (4-methyl-pyridine-N-oxide)2 molecules which have a distorted trigonal-bipyramidal geometry. The thallium atom is coordinated to two iodine atoms and a bromine atom in equatorial positions, and by two 4-methyl-pyridine-N-oxide ligands in the axial positions.

Direct Electrochemical Synthesis of Pyrimidine-2-thionato Complexes of Zinc(II) and Cadmium(II): The Crystal Structure of (1,10-Phenanthroline)bis(pyrimidine-2-thionato)cadmium(II)

Zn(pymt)2 and Cd(pymt)2 complexes have been obtained by electrochemical oxidation of anodic zinc or cadmium in acetonitrile solutions of pyrimidine-2-thione (Hpymt). When 2,2′-bipyridine (bipy) or 1,10-phenanthroline (phen) was added to the electrochemical cell, the adducts [M(pymt)2(bipy)], or [M(pymt)2(phen)] (M = Zn or Cd) were obtained. Crystals of [Cd(pymt)2phen] are orthorhombic, with a = 9.882(2), b = 12.491(1), c = 16.513(2)Å, space group P212121 and Z = 4. The cadmium atom has distorted octahedral geometry, and one nitrogen atom of each pyrimidine-2-thiolato ligand is not coordinated.

Darstellung, Eigenschaften und Kristallstruktur von [Diaqua-1,6-bis(benzimidazol-2-yl)-2,5-dithiahexan-nickel(II)]dibromid-Dihydrat / Synthesis, Properties and Molecular Structure of [Diaqua-1,6-bis(benzimidazol-2-yl)-2,5-dithiahexane-nickel(I I)]dibromide Dihydrate

The synthesis, crystal structure and some spectroscopic properties of [Ni(BBDH)(OH2)2]Br2.2 H2O, (BBDH = 1,6-bis(benzimidazol-2-yl)-2,5-dithiahexane), are reported. The compound is obtained from nickel bromide hydrate and BBDH in ethanol. It crystallizes in the triclinic space group P 1̄ with a = 1155.5(3), b = 1203.9(2), c = 1047.0(2) pm, α = 111.62(4), β = 114.25(2), γ = 86.74(3)°, and Z = 2. The structure consists of [Ni(BBDH)(OH2)2]2+ cations joined through hydrogen bonding to two Br- ions and two molecules water of crystallization. BBDH is bound to the Ni2+ ion as quadridentate ligand with two N atoms of the two imidazole moieties in axial positions and the two S atoms in equatorial arrangement. The sixfold coordination is completed by two water molecules in trans-position to the S atoms. Raman, IR and mass spectra are discussed.

Ternary copper(II) complexes with N-carboxymethyl-l-prolinato(2−) ion and imidazole or creatinine: A comparative study of the interligand interactions influencing the molecular recognition and stability

The compounds {[Cu(CMP)(Him)].H(2)O}(n) (I) and [Cu(CMP)(crea)H(2)O].3H(2)O (II) were synthesized and characterized by X-ray diffraction, thermal, spectral and magnetic methods (CMP=N-carboxymethyl-;l-prolinato(2-) ion, Him=imidazole and crea=creatinine). Appropriate structural comparison with other compounds such as {[Cu(CMP)(H(2)O)].H(2)O}(n), [Cu(crea)(2)Cl(2)] and [Cu(dipeptide)(crea)(H(2)O)(x)].nH(2)O (x=0 or 1) have been made in order to prove that crea can act as an imidazole-like ligand (because it is able to promote the same fac- to mer-CMP tridentate conformational change in copper(II) complexes) as well as to discuss the interligand interactions which control the 'Cu(CMP) complex-crea, molecular recognition processes. In contrast to that found in related ternary complexes, we have concluded that direct CMP-crea interligand interactions are missing in the Cu-CMP-crea complex due to the inappropriate correspondence between the donor and/or acceptor H-bonding properties of these ligands. CMP can only act as H-acceptor by its two terminal carboxylate group, and crea can display H-donor and H-acceptor roles by its exocyclic -NH(2) and O moieties, respectively. That promotes the reinforcement of the Cu-N(crea) bond by a bridge -N-H(crea)...O(aqua) (2.867(3)A, 176.4 degrees).

Functional Superoxide Dismutase Mimics. Structural Characterization and Magnetic Exchange Interactions of Copper(II)−N-Substituted Sulfonamide Dimer Complexes

Dinuclear copper(II) complexes with N-substituted sulfonamide ligands as superoxide dismutase (SOD) mimics have been investigated. The new N-(thiazol-2-yl)toluenesulfonamide (Htz-tol) and N-(thiazol-2-yl)naphthalenesulfonamide (Htz-naf) ligands have been prepared and structurally characterized. The complexes derived from these ligands, [Cu(2)(tz-tol)(4)] (1) and [Cu(2)(tz-naf)(4)] (2), have been synthesized, and their crystal structure, magnetic properties, and EPR spectra were studied in detail. In both compounds the metal centers are bridged by four nonlinear triatomic NCN groups. The coordination geometry of the coppers in the dinuclear entity of 1 and 2 is distorted square planar with two N-thiazole and two N-sulfonamido atoms. Magnetic susceptibility data show a strong antiferromagnetic coupling, with -2J = 121.3 cm(-1) for compound 1 and -2J = 104.3 cm(-1) for compound 2. The EPR spectra of the polycrystalline samples of compounds 1 and 2 have been measured at the X- and Q-band frequencies at different temperatures. Above 20 K the spectra are characteristic of S = 1 species with zero-field splitting parameter D = 0.230 cm(-1) for compound 1 and 0.229 cm(-1) for compound 2. The EPR parameters are discussed in terms of the known binuclear structures. The complexes exhibit high SOD activity, as shown by the low IC(50) values obtained with the xanthine/xanthine oxidase/NBT assay: 0.13 microM for compound 1; 0.17 microM for compound 2.

X-ray, spectral and biological (antimicrobial and superoxide dismutase) studies of oxalato bridged CuII–NiII and CuII–ZnII complexes with pentamethyldiethylenetriamine as capping ligand

X-band electron spin resonance (ESR) and electronic spectra of oxalatobridged heterodinuclear Cu-Ni and Cu-Zn complexes, viz., [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN and [(PMDT)Cu-Ox-Zn(PMDT)](BPh(4))(2).2CH(3)CN, where PMDT=pentamethyldiethylenetriamine, Ox=oxalate ion have been described. Complex [(PMDT)Cu-Ox-Ni(PMDT)](BPh(4))(2).2CH(3)CN has been structurally characterized. This complex crystallizes in the monoclinic space group, C(2) (No. 5) with the unit parameters a=20.445(4) A, b=14.884(3) A, c=23.174(5) A, alpha=90 degrees, beta=102.693(4) degrees, gamma=90 degrees, V=6880(2) A(3) and Z=4. The structure refined to R=0.0354 and R(w)=0.0853 for 21,109 reflections with I>2 sigma(I) using 765 parameters, shows the presence of a MN(3)O(2) chromophore in a distorted trigonal-bipyramidal (TBP) heterometallic complex with oxalate dianion. Taking with an equatorial Cu-O=2.137(8) A and an axial Cu-O=1.961(6) A coordination site at Cu(II) ion and equatorial Ni-O=2.178(7) A and axial Ni-O=1.994 (9) A coordination site at Ni(II) ion. The Cu-Ni distance is 5.3532(9) A and Cu-C(2)O(4)-Ni unit is planar. The [(PMDT)Cu-Ox-Ni(PMDT)](2+) shows the ESR spectrum of the antiferromagnetic spin exchange with each dinuclear delocalization of the unpaired electron over the unit and spin-doublet ground state which demonstrates the Cu-Ox-Ni core. Antimicrobial and superoxide dismutase (SOD) activities of these complexes have also been measured.

Oxidative cleavage of DNA by a new ferromagnetic linear trinuclear copper(II) complex in the presence of H2O2/sodium ascorbate

A new trinuclear copper(II) complex has been synthesized and structurally characterized: [Cu(3)(L)(2)(HCOO)(2)(OH)(2)](infinity) (HL = (N-pyrid-2-ylmethyl)benzenesulfonylamide). In the complex, the central copper ion is six-coordinated. The coordination spheres of the terminal copper atoms are square pyramidal, the apical positions being occupied by a sulfonamido oxygen of the contiguous trimer. As a consequence, the complex can be considered a chain of trinuclear species. The three copper atoms are in a strict linear arrangement, and adjacent coppers are connected by a hydroxo bridge and a bidentate syn-syn carboxylato group. The mixed bridging by a hydroxide oxygen atom and a bidentate formato group leads to a noncoplanarity of the adjacent basal coordination planes with a dihedral angle of 61.4(2) degrees. Susceptibility measurements (2-300 K) reveal a strong ferromagnetic coupling, J = 79 cm(-1), leading to a quartet ground state that is confirmed by the EPR spectrum. The ferromagnetic coupling arises from the countercomplementarity of the hydroxo and formato bridges. The trinuclear complex cleaves DNA efficiently, in the presence of hydrogen peroxide/sodium ascorbate. tert-Butyl alcohol and sodium azide inhibit the oxidative cleavage, suggesting that the hydroxyl radical and singlet oxygen are involved in the DNA degradation.

Intramolecular "Aryl-metal chelate ring" pi,pi-interactions as structural evidence for metalloaromaticity in (aromatic alpha,alpha'-diimine)-copper(II) chelates: molecular and crystal structure of aqua(1,10-phenanthroline)(2-benzylmalonato)copper(II) three-hydrate

By reaction of Cu(2)CO(3)(OH)(2), 2-benzylmalonic acid (H(2)Bzmal), and 1,10-phenanthroline (phen), [Cu(Bzmal)(phen)(H(2)O)] x 3H(2)O (compound 1) has been obtained and characterized by thermal, spectral, magnetic, and X-ray diffraction methods. The molecular structure of 1 is remarkably similar to that of [Cu(Bzmal)(bipy)(H(2)O)] x 2H(2)O (compound 2, bipy = 2,2'-bipyridine). In both complexes, the aryl(Bzmal) ring produces an unexpected pi,pi-stacking interaction with the Cu(II)-(aromatic alpha,alpha'-diimine) chelate ring, at an average distance d(pi)(-)(pi) of 3.40 A, involving roughly parallel and smoothly slipped rings. This insight is discussed as new structural evidence for metalloaromaticity of Cu(II)-(aromatic alpha,alpha'-diimine) chelate rings. Interestingly, 1 recognizes itself by a weak intermolecular pi,pi-stacking interaction between aryl(Bzmal) ligands to give pairs of complex molecules. In contrast, there is an intermolecular pyridyl-pyridyl pi,pi-stacking interaction also forming pairs of complex molecules in 2.

Complexes of Ni(II) and Cu(II) with ofloxacin. Crystal structure of a new Cu(II) ofloxacin complex

Several coordination compounds formed between Ni(II) or Cu(II) with ofloxacin have been synthesised and characterised. According to elemental chemical analysis and FT-IR spectroscopy data, direct reaction of Ni(II) and Cu(II) salts with ofloxacin leads to formation of precipitates for which mass spectrometry demonstrates their polymeric nature. However, crystalline [Cu(oflo)2(H2O)].2H2O is formed if the reaction is carried out in the presence of ammonia. This complex crystallises in the triclinic system, space group P-1 with a=9.2887(12), b=11.2376(14), c=17.874(2) A, alpha=92.12(3), beta=95.39(3), gamma=91.71(3) degrees and Z=2. The local geometry around the Cu(II) ion is a slightly distorted square base pyramid. Electronic spectra, magnetic susceptibility measurements and EPR spectra of the synthesised complexes indicate a tetragonal environment.

Copper(II) complexes with 4-amino-N-[4,6-dimethyl-2-pyrimidinyl]benzenesulfonamide. Synthesis, crystal structure, magnetic properties, EPR, and theoretical studies of a novel mixed mu-carboxylato, NCN-bridged dinuclear copper compound

New Cu(II) complexes of sulfamethazine (4-amino-N-[4,6-dimethyl-2-pyrimidinyl]benzenesulfonamide, HL) [Cu(2)(CH(3)COO)(2)(L)(2)].2dmf (1) and ([Cu(L)(2)].2H(2)O)(infinity) (2) were prepared and structurally characterized. Compound 1 crystallizes in the monoclinic system, space group P2(1)/n, with a = 8.9486(9) A, b = 15.0956(12) A, c = 16.542(3) A, beta = 105.584(15) degrees, and Z = 2. Compound 2 crystallizes in the monoclinic system, space group P2(1)/c, with a = 13.8097(8) A, b = 14.5765(4) A, c = 13.7853(15) A, beta = 96.033(9) degrees, and Z = 1. In compound 1 two copper ions are linked by two syn-syn acetates and two nonlinear NCN bridging groups pertaining to the deprotonated sulfamethazine ligands. Each copper center presents a nearly square planar geometry. Magnetic susceptibility data for 1 show a strong antiferromagnetic coupling with 2J = -216.7 cm(-)(1). The EPR spectra at the X- and Q-band frequencies present the signals corresponding to the dinuclear entity, being the zero-field splitting parameter, D = 0.265 cm(-)(1). The antiferromagnetic exchange coupling is discussed using DFT calculations on some model compounds with NCN bridging ligands and also on model structures with mixed mu-acetato and NCN bridges. The copper in the polymeric compound 2 is five coordinate. The CuN(5) chromophore has a highly distorted square pyramidal geometry with small axial N-Cu-N angles of 65.53(14) and 59.90(13) degrees. In the structure a sulfamethazinate anion binds to one copper through the sulfonamido and pyrimidine N atoms and to an adjacent copper via the amino N atom.

Interactions of metal ions with a 2,4-diaminopyrimidine derivative (trimethoprim). Antibacterial studies

The interaction of copper (II), zinc(II) and cadmium(II) with Trimethoprim (2,4-diamino-5-(3',4',5'-trimethoxybenzyl) pyrimidine) has been studied. The crystal structures of [Zn(Trim)2Cl2] (2) and [Cd(Trim)Cl2(CH3OH)]n (4) are reported. Compound (2) exhibits a distorted tetrahedral environment around the metal center and crystallizes in the triclinic space group P1 with a=10.2397(6), b=10.4500(6), c=16.3336(16) A, alpha=96.141(8), beta=106.085(5), gamma=96.551(5) degrees and Z=2. In complex (4), the Cd(II) centers are bridged sequentially by two chlorine ions to form infinite chains and present a six-coordinated environment; the compound crystallizes in the monoclinic P2(1)/C space group with a=13.958(5), b=7.532(2), c=18.390(2) A, alpha=90, beta=97.32(5), gamma=90 degrees and Z=4. In both structures the Trimethoprim acts as a monodentate ligand through the pyrimidinic nitrogen N(1) atom. The characterization of the Cu(Trim)2(CH3O)(ClO4) complex through EPR and magnetic measurements suggests a binuclear or polinuclear nature, with bridging methoxo groups. The complexes were screened for their activity against several bacteria, showing activity similar to that of trimethoprim.

Countercomplementarity and strong ferromagnetic coupling in a linear mixed mu-acetato, mu-hydroxo trinuclear copper(II) complex. Synthesis, structure, magnetic properties, EPR, and theoretical studies

The structural and magnetic data of the trinuclear compound [Cu3(L)2(CH3COO)2(OH)2(dmf)2] (HL = N-(2-methylpyridyl)toluensulfonylamide) are reported. The compound crystallizes in the monoclinic system, space group P2(1)/n (no. 14), with a = 11.6482(6) A, b = 13.5772(6) A, c = 13.5306(7) A, alpha = 90 degrees, beta = 92.859(5) degrees, gamma = 90 degrees, and Z = 2. The three copper atoms form an exact linear arrangement. Neighboring coppers are connected by a hydroxo bridge and a bidentate syn-syn carboxylato group. The coordination spheres of the terminal copper atoms are square pyramidal with a dmf molecule as the apical ligand. The central copper has a regular square planar geometry. The mixed bridging by a hydroxide oxygen atom and a bidentate carboxylato group leads to a noncoplanarity of the adjacent basal coordination planes with a dihedral angle of 51.96(9) degrees. Susceptibility measurements (2-300 K) reveal a strong ferromagnetic coupling, J = 93(6) cm-1, in the mixed-bridged moiety leading to a quartet ground state that is confirmed by the EPR spectra. The ferromagnetic exchange coupling is discussed using DFT calculations on model compounds that have shown a countercomplementary effect of the hydroxo and acetate bridges.

Synthesis, structure, spectroscopic properties and biological activity of mixed diorganotin(IV) complexes containing pyridine-2-carbaldehyde thiosemicarbazonato and diphenyldithiophosphinato ligands

Reaction of the title ligands (HPyTSC and HS(S)PPh2, respectively) with R2SnO (R = Me, Et, Bu) in ethanol (EtOH) afforded the complexes [SnMe2(PyTSC) (S2PPh2)].EtOH (1) and [SnR2(PyTSC) (S2PPh2)] (R = Et (2), Bu (3)). The structures of 1 and 2 were determined by single-crystal X-ray diffractometry. In both these complexes the tin atom is coordinated to an N,N,S-dentate thiosemicarbazonate ligand, an anisobidentate dithiophosphinato ligand and the two R groups. The coordination polyhedrons can be described as distorted pentagonal bipyramids. A comparative study of the IR spectra of 1, 2 and 3 indicates that the butyl complex has a similar structure. Multinuclear (1H, 13C, 31P and 119Sn) NMR data suggest that the structures of 1 and 2 probably remain in CDCl3 (or DMSO-d6) solution but compound 3 partially decomposes in these media. Preliminary results on the effects of the complexes on the proliferation and differentiation of FLC, CEM, U937, K562 and TOM-1 leukaemia cells, and on the clonogenic activity of K562 cells are also described.