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The alkali metal (Li + , Na + , K + , Rb + , Cs + ) carboxylate-dithiocarbamate complexes of L -proline have been prepared from the reaction of L -proline with carbon disulfide in the presence of two equivalents of the corresponding alkali metal hydroxide. The resulting compounds have been characterized by FAB + mass spectrometry, IR spectroscopy, NMR ( 1 H, 13 C) spectroscopy. The X-ray single crystal crystallography analysis of the complexes of K + , Rb + and Cs + complexes showed that the coordination modes of dithiocarbamate and carboxylate groups to the alkali metal is modulated by the resonance effect, the ionic radius of the sulfur and oxygen atoms as well as the size, charge-density, and Lewis-acidity of the metal ions. In this way in the solid state polymeric structures in 2D for K + and Rb + complexes, and 3D in the case of Cs + are generated. The distances C···M, M···S1 and M···S2 suggest the existence of cation···π and van der Waals interactions that can be described as a η 3 coordination mode of the dtc group to the alkali metal ions.

The syntheses and characterization of six new triorganotin(IV) complexes, Ph3Sn(PrACDA) (1), Bu3Sn(PrACDA) (2), Ph3Sn(BzACDA) (3), Bu3Sn(BzACDA) (4), Me3Sn(BzACDA) (5) and Cy3Sn(BzACDA) (6) (ACDA = 2-amino-1-cyclopentene-1-carbodithioate anion) are reported. Compounds 1–6 were synthesized by the reaction between the sodium salts of 2-N-propyl- or 2-N-benzyl-2-amino-1-cyclopentene-1-carbodithioate and R3SnCl (R = Ph, Bu, Me, Cy) in a 1:1 M ratio. The complexes were characterized by elemental analyses, IR and NMR (1H, 13C and 119Sn) spectroscopy and by FAB+ mass spectrometry. The experimental data reveal that the tin atom is coordinated to the ligand by means of the two sulfur atoms from the carbodithioate group in an anisobidentate mode, while the 119Sn{1H} NMR spectra suggest a pentacoordinate metal center in 1–4 and a tetracoordinate tin atom for 5 and 6. The molecular structures of complexes 1, 3 and 5 were confirmed by single crystal X-ray diffraction analysis showing the presence of N–H···S hydrogen bonding and a distorted trigonal bipyramid geometry for the tin atoms.

Eighteen mononuclear diorganotin(IV) complexes derived from tridentate Schiff bases and R2SnO (IV) oxides (R = Me, n-Bu, Ph) were synthetized by multicomponent reactions in moderate yields. Complexes were characterized by common spectroscopic techniques such as FT-IR, UV–vis, mass spectrometry and NMR (1H, 13C and 119Sn) spectroscopy analysis. Nine complexes were characterized by single crystal X-ray diffraction analysis (1c, 1d, 1g, 1k, 1n, 1o, 1p, 1q and 1r). 119Sn NMR spectra showed signals at δ = 135–145, 175–185 and 319–323 ppm for Me, n-Bu and Ph derivatives respectively, indicating the pentacoordination of the tin atoms. In solid state, for compounds 1c, 1d, and 1g a distorted octahedral geometry for tin atoms was observed owing the presence of intermolecular Sn⋯O interactions, while for compounds 1k, 1n-1r, the pentacoordinate environment for tin atoms is observed. At supramolecular level the presence of O H⋯O, C H⋯O, C H⋯X (X = Cl, Br), C H⋯π and π⋯π interactions allow the formation of 1D and 2D polymeric chains.

The combination of one dipyridyl linker [1,2-di(4-pyridyl)ethylene (DPE), 1,2-di(4-pyridyl)ethane (DPEt), or 4,4′-azopyridine (DPA)] with two molecules of arylboronate ester 1 produced dinuclear Lewis-type N→B adducts that can act as acyclic host for polycyclic aromatic hydrocarbons (PAHs) in the solid state. Nine crystalline solids of composition PAH@adduct (i.e., one PAH per adduct) were obtained from solutions containing a single PAH. On the basis of the single-crystal X-ray diffraction analysis of the compound ANT@A1 (ANT = anthracene; A1 = adduct being composed of DPE and two boronate esters 1), the PAH inclusion selectivity is related to a size-fitting adaptation to an octaedral-shaped pocket assembled by CH-π interactions between fragments of the diamine and the arylboronate ester 1. The resulting reversible organic clathrates can perform “catch and release” cycles of PAHs such as pyrene and can sequester selectively PAHs from mixtures in solution.

Six new diorganotin (IV) complexes, [Ph2Sn(Pr-ACDA)2] 1, [Bu2Sn(Pr-ACDA)2] 2, [Ph2Sn(Bz-ACDA)2] 3, [Bu2Sn(Bz-ACDA)2] 4, [Me2Sn(Bz-ACDA)2] 5, [t-Bu2Sn(Bz-ACDA)2] 6 are reported (where ACDA is the 2-amino-1-cyclopentene-1-carbodithioic anion). The diorganotin complexes were prepared from reactions between sodium N-propyl and N-benzyl-2-amino-1-cyclopentene-1-carbodithioate with R2SnCl2 (R=Ph, Bu, Me, tBu) in a 2:1 ratio. All complexes were characterized by elemental analysis, IR, multinuclear NMR (1H, 13C, and 119Sn), FAB+ mass spectrometry and in the case of 2, 3 and 5 by single-crystal X-ray diffraction. Both solution and solid state studies show that dithioacid ligands are coordinated to tin in an aniso-bidentate manner. In all complexes coordination takes place only through the carbodithioate moieties. 119Sn NMR data indicate pentacoordination of tin in solution. The tin coordination geometry, in all three structures is a highly distorted octahedral geometry, where tin is bonded to the four sulfur atoms of the two aniso-bidentate carbodithioate ligands in the equatorial plane and the organic substituents on tin atom in trans-positions. In addition, the crystal structures show the presence of N-H…S hydrogen bonding contacts.

The possibility of using less expensive and nontoxic metals, such as copper, as substitutes for more expensive heavy metals in the synthesis of new transition-metal complexes to be used as sensitizers in dye-sensitized solar cells (DSSCs) has stimulated research in this field. The novel photoluminescent copper(I) complex bis(triphenylphosphane-κP)[trans-(±)-2,4,5-tris(pyridin-2-yl)-2-imidazoline-κ2 N 2,N 3]copper(I) hexafluorophosphate, [CuI(C18H15N5)(C18H15P)2]PF6, has been successfully synthesized and characterized by IR and 1H NMR spectroscopy, as well as by single-crystal X-ray diffraction and thermogravimetric analysis. The complex showed interesting photophysical properties, which were studied experimentally in solution and in the solid state by UV–Vis and fluorescence spectroscopy. Density functional theory (DFT) calculations with dichloromethane as solvent reproduced reasonably well the HOMO and LUMO orbitals of the title compound.

The combination of racemic praziquantel, (RS)-PZQ, with aliphatic dicarboxylic acids of the homologous series HOOC–(CH2)n–COOH (with n = 0–8) and the unsaturated analogues of succinic acid as cocrystal formers via liquid-assisted grinding provided a total of nine 1:1 and 2:1 cocrystals with oxalic acid, malonic acid, succinic acid (two polymorphic phases), maleic acid, fumaric acid, glutaric acid, adipic acid, and pimelic acid. The cocrystalline phases were identified first by XRPD analysis and then structurally characterized by IR spectroscopy and, as far as possible, by single-crystal X-ray diffraction analysis. Crystals suitable for XRD analysis were obtained for seven cocrystals and, additionally, for (RS)-PZQ. The analysis of the supramolecular interactions in the crystal structures has shown that the dominant hydrogen bonding patterns within the cocrystals are heterodimeric motifs formed through O–H···O hydrogen bonds between PZQ and the dicarboxylic acids, which mostly contain additionally at least...

Sodium tetraphenylimidodiphosphinochalcogenide salts Na[(Ph2P(X)NP(X)Ph2)] (X = S, Se), react with 15-crown-5 ether to give two complexes [Na(15C5)][(Ph2P(X)NP(X)Ph2)] (X = S, Se), 1 and 2 respectively. The crystal and molecular structures of the resulting compounds were determined by X-ray diffractometry. The compounds are isostructural showing sodium–sulfur and sodium–selenium interactions, respectively, forming discrete inorganic (carbon free) chelate rings. These are different from the complex from the oxygen homolog which is an aggregated poly-ion, containing sodium ions with different coordination environments.

Five new chlorodiorganotin(IV) complexes derived from dithiocarbamate ligands have been prepared and structurally characterized. The complexes 1–5 with the general formula {(Ph2SnCl)dtc} (dtc = R1R2NCS2−; 1, R1 = Bn, R2 = 9-anthrylmethyl; 2, R1 = Bn, R2 = 9-phenanthrylmethyl; 3, R1 = Bn, R2 = 1-pyrenylmethyl; 4, R1 = 1-naphthylmethyl, R2 = 1-pyrenylmethyl; 5, R1 = R2 = 1-pyrenylmethyl) have been obtained from Ph2SnCl2 and the sodium dithiocarbamate salts of benzyl(9-anthrylmethyl)amine, benzyl(9-phenanthrylmethyl)amine, benzyl(1-pyrenylmethyl)amine, 1-naphthylmethyl(1-pyrenylmethyl)amine and di(1-pyrenylmethyl)amine. Compounds 1–5 have been analyzed as far as possible by elemental analysis, FAB+ mass spectrometry, IR, UV–Vis, fluorescence and NMR (1H, 13C, 119Sn) spectroscopy, and single-crystal X-ray diffraction analysis (1–3). The solid-state and solution studies showed that the dtc ligands are coordinated to the tin atoms in the anisobidentate manner. In all cases the metal centers are five-coordinate. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedra with τ-values in the range of 0.49–0.55. The crystal structures show the presence of C–H···Cl, C–H···S, C–H···π, offset π–π and S···π contacts. The stability of the (Ph2SnCl)dtc complexes in the presence of the acetate anion has been examined in acetonitrile solutions. For all of these organotin(IV) complexes the displacement of the coordinated ligands (i.e., chloride and dtc) by the acetate anion was observed. The lability, as well as their intrinsic fluorescent properties of the polyaromatic moieties in these (Ph2SnCl)dtc compounds make them interesting candidates to detect the presence of O-donor anions at very low concentrations by displacement of the metal-coordinated dtc.

Thirteen new stannacyclododecane dithiocarbamate complexes have been prepared by reacting 12-chloro-12-n-butyl-1,11-dioxa-4,8-dithia-12-stannacyclododecane (1) and 12-chloro-12-n-butyl-1,4,8,11-tetrathia-12-stannacyclododecane (2) with pyrrolidine-, morpholine-, thiomorpholine-, piperidine-, piperazinebis-, and 3-pyrroline-carbodithioates, respectively, as well as with diethyl-dithiocarbamate. All complexes were characterized by elemental analyses, IR, EI-MS, and NMR (1H, 13C, and 119Sn) studies. The spectroscopic data suggest the replacement of the chlorides by the corresponding dithiocarbamates with monodentate coordination, leading to six-coordinate tin atoms in all the cases.

Five metal complexes have been prepared by reacting 3- and 4-pyridineboronic acid (3- and 4-pba) with potassium tetrachloroplatinate (K2PtCl4) and hexachloroplatinic(IV) acid hydrate (H2PtCl6·aq): [4-pbaH]2[PtCl4], [3-pbaH]2[PtCl4], [4-pbaH][Pt(4-pba)Cl3], cis-[Pt(4-pba)2Cl2]·H2O, and cis-[PtIV(3-pba)2Cl4]·2H2O. All compounds have been characterized by single-crystal X-ray diffraction analysis, showing that the primary hydrogen bonding interactions of the resulting 1D, 2D, and 3D networks contain at least one of the following synthons: X-H···Cl2Pt− (X = C, N+), B(OH)2···Cl2Pt−, and B(OH)2···(HO)2B. The dimensions are enhanced further by secondary +N−H···ClPt, O−H···O, and O−H···ClPt hydrogen bonding interactions between donor and acceptor atoms located at the periphery of these synthons. Additional weak C−H···O, C−H···Cl, B···N, and π···π stacking interactions stabilize the crystal structures further.

One dinuclear chlorodiphenyltin (IV) dithiocarbamate complex (1) and four mononuclear complexes of general formula Ph2Sn(S2CNR)Cl (2, 3, 5, and 6) have been synthesized and characterized both in solidstate and solution. X-ray structures for complexes 1, 3 and 6 demonstrated a five-coordination geometry around of tin atoms, in which dithiocarbamate ligand chelates asymmetrically the metal center. As shown by 119 Sn NMR spectroscopy, five-coordination geometry observed in the solid-state remains in solution. The stability of these chlorodiphenyltin(IV) dithiocarbamate complexes in the presence of biologically relevant anions such as acetate, dicarboxylates of general formula � OOC-(CH2)n-COO � (n = 2–8), dihydrogenphosphate, hydrogensulfate, and halides has been examined in acetonitrile solutions. For all of these organotin(IV) complexes the displacement of the coordinated ligands (i.e., chloride and dithiocarbamate) from the organotin(IV) moiety occurred in the presence of monoanions like acetate, dihydrogenphosphate, hydrogensulfate and fluoride. A stepwise mechanism for ligand exchange is proposed based on UV–Vis, 1

This contribution describes metal-organic frameworks based on cadmium-clusters that are capable of generating double-pillared architectures. A brief overview of the literature concerning such systems is presented together with the description of three new coordination polymers, [{[Cd2(trans-1,2-a,a-chdc)(trans-1,2-e,e-chdcH)2(4,4′-bpy)2]·8H2O}n] (1), [{Cd2(trans-1,4-e,e-chdc)(trans-1,4-a,a-chdc)(4,4′-bpe)2}n] (2) and[{[Cd2(cis,cis-1,3,5-chtc)(HCO2)(H2O)(4,4′-bpy)2]·DMF·4H2O}n] (3) [1,2-chdc = 1,2-cyclohexanedicarboxylate, 1,4-chdc = 1,4-cyclohexanedicarboxylate, 1,3,5-chtc = 1,3,5-cyclohexanetricarboxylate, 4,4′-bpy = 4,4′-bipyridine and 4,4′-bpe = (E)-1,2-bis(4-pyridyl)ethylene]. Compound 1 has a double-pillared two-dimensional layer structure, while compounds 2 and 3 are double-pillared three-dimensional frameworks. All materials have been characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis. The robustness of the open-frameworks found for compounds 1 and 3 has been examined by X-ray powder diffraction of dried samples, which showed that the crystal structure of the 2D coordination polymer 1 collapses whereas the 3D architecture of compound 3 remains intact. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

An efficient synthesis of enantiomerically-pure β-aryl-γ-lactams is described. The principal feature of this synthesis is the practical resolution of β-aryl-γ-lactams with (S)-Naproxen. The procedure is based on the Michael addition of nitromethane to benzylidenemalonates, which was easily obtained, followed by the reduction of the γ-nitroester in the presence of Raney nickel and the subsequent saponification/decarboxylation reaction. The utility of this methodology was highlighted by the preparation of enantiomerically-pure (R)- and (S)-Baclofen hydrochloride.

In the title compound, C14H10N2O2, the phtalimide and 2-pyridylmethyl units are almost perpendicular, with an interplanar angle of 85.74 (2)°. In the crystal, molecules are linked by weak C—H...O interactions, forming chains running along the b axis. The packing is further stabilized by offset π–π interactions between adjacent pyridine rings, with a centroid–centroid distance of 3.855 (2) Å.

Reaction of 2,3-dihydro-4(1H)-quinazolinones with NBS, Br2/Et3N and NCS yields 6,8-Br/Cl-2,3-dihydro-4(1H)-quinazolinones with moderate to good yield. The method does not require a catalyst and offers extremely short reaction time. INTRODUCTION 2,3-Dihydro-4(1H)-quinazolinones form an important class of bioactive compounds and these can easily be oxidized to their quinazolin-4(3H)-one analogues. 1 In general, the derivatives of the quinazolinones are considered as an important building blocks 2 for a large number of diverse alkaloids 3 and present a wide range of biological and pharmaceutical activities. 4 In addition, numerous efforts of synthesis have been made to obtain halogenated quinazolinones for their pharmacophoric effect. 5 For example, the incorporation of a fluorine or chlorine atom into an active compound results in beneficial changes in molecular properties such as higher fat solubility giving different absorption and transport rate, altered electronic effects, improved stability, and equivalent steric size. 6 On the other hand, quinazolinones halogenated with bromine have shown their importance as building blocks in the synthesis of compounds with biological activity. 7 In the literature, to obtain halogenated quinazolinones one first treats anthranilic acid (a) with bromine in presence of acetic acid or sulfuryl chloride to form the monoand di-halogenated derivatives b and c, HETEROCYCLES, Vol. 85, No. 9, 2012 2173