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This work provides the coordination chemistry of the resulting compound of 2-(2-furyl)-3-hydroxychromone and nicotinoyl chloride with first row transition metal ions. Good performance in H2 evolution was shown by the copper-containing photocatalyst.

Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(μ-isothiocyanato-κ2 N:S)(μ4-pyrimidine-2-thiolato-κ6 N 1,S:S:S:S,N 3)lead(II)], [Pb(C4H3N2S)(NCS)] n or [Pb(Spym)(NCS)] n , (I), and the polymeric one-dimensional (1D) compound catena-poly[[μ4-bromido-di-μ-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)] N,N-dimethylformamide monosolvate], {[Pb2Br3(C4H3N2S)(C4H4N2S)]·C3H7NO} n or {[Pb2Br3(Spym)(HSpym)]·DMF} n , (IIa), respectively. Poly[μ4-bromido-di-μ3-bromido-(μ-pyrimidine-2-thiolato-κ3 N 1,S:S)(μ-pyrimidine-2-thione-κ3 N 1,S:S)dilead(II)], [Pb2Br3(C4H3N2S)(C4H4N2S)] n or [Pb2Br3(Spym)(HSpym)] n , (IIb), could be obtained as a mixture with (IIa) when using a lesser amount of solvent. In the crystal structures of the pseudohalide/halide PbII stable compounds, coordination of anionic and neutral HSpym has been observed. Both Spym− (in the thiolate tautomeric form) and NCS− ligands were responsible for the two-dimensional (2D) arrangement in (I). The Br− ligands establish the 1D polymeric arrangement in (IIa). Eight-coordinated metal centres have been observed in both compounds, when considering the Pb...S and Pb...Br interactions. Both compounds were characterized by FT–IR and diffuse reflectance spectroscopies, as well as by powder X-ray diffraction. Compound (IIa) and its desolvated version (IIb) represent the first structurally characterized PbII compounds containing neutral HSpym and anionic Spym− ligands. After a prolonged time in solution, (IIa) is converted to another compound due to complete deprotonation of HSpym. The structural characterization of (I) and (II) suggests HSpym as a good candidate for the removal of PbII ions from solutions containing thiocyanate or bromide ions.

2-(2-Furyl)-3-hydroxychromone (HL) reacts with MII ions in the formation of quadratic [Cu(L)2] (3), octahedral [M(L)2(OH2)2] (M = Co (1), Ni (2), Zn (4), Mn (5)) and seesaw [M(L)2] (M = Sn (6), Pb (7)) complexes. Recrystallization of complexes 1-3 in presence of pyridine lead to [M(L)2(py)2] (1a-3a) adducts. All compounds were characterized by Fourier transform infrared spectroscopy (FTIR). Complexes 1-7 were analyzed by UV-Vis and diffuse reflectance spectroscopies. The estimated band gap energies range from 2.90-3.15 eV. The crystal structure of complexes 6 and 7 revealed the influence of the stereochemically active lone pair due to their electronic configuration ns2. An intense fluorescence emission band centered at approximately 600 nm (λexc centered at 340 nm) has been observed for complex 6 in the solid state. In N,N‑dimethylformamide (DMF) solution, complex 6 showed two emission bands (468 and 538 nm) when excited from 300 to 380 nm, and only one emission band (468 nm) when excited from 385 to 420 nm.

Pyrimidine-2-thione (HSpym) reacts with lead(II) thiocyanate and lead(II) bromide in N,N-dimethylformamide (DMF) to form poly[(μ-isothiocyanato-κ

This study investigated the synthesis and structural characterization of mercury(II) selenolate molecular clusters and mixed mercury(II) seleninate/selenolate polymeric clusters. The novel tetranuclear mercury(II) selenolate molecular clusters [Hg4Br4(SePh)4(phen)2] (1) and [Hg4I4(SePh)4(phen)2] (2) were prepared by reacting Hg(SePh)2 with mercury salts and 1,10-phenanthroline. The mixed mercury(II) seleninate/selenolate polymeric clusters [Hg2Br(O2SePh)(SePh)2]n (3) and [Hg2I(O2SePh)(SePh)2]n (4) were synthesized by reacting Hg(SePh)2 with 3-chloroperbenzoic acid and mercury salts. Compounds 3 and 4 represent new examples of extended one-dimensional chains of closed ME (M = mercury; E = Se) systems, which result from the partial oxidation of mercury phenylselenolate clusters. The compounds 1 − 4 have been characterized by spectroscopic and crystallographic methods. Optical band gap values for 1 − 4 were estimated by UV–vis spectroscopy in the solid state.

2,6-Diacetylpyridine-bis(benzoylhydrazone), H2LPh, reacts with Pb(OAc)2·3H2O and NEt3 as a supporting base forming a polymeric solid of the composition [Pb(LPh)]n. A reaction with pyridine results in cleavage of the polymer and formation of the dimeric, crystalline compound [Pb(py)(LPh)]2. Similar reactions with PbX2 salts (X = Cl, Br, I) also give almost insoluble solids of the tentative composition [Pb(H2LPh)X2]n. After ongoing reactions with DMSO, single deprotonation of the organic ligand and the formation of pseudo-dimeric [Pb(HLPh)X]2 complexes was observed. Depending on the presence of solvent molecules they form different supramolecular aggregates by π–π interactions. The use of Pb(NO3)2 results in a dimeric structure with relatively short Pb–O bonds of 2.442(2) A between the monomeric sub-units. The formed dimers aggregate to a polymeric assembly by hydrogen bonds. The products were studied by spectroscopic methods and X-ray diffraction.

Aroylhydrazones ofortho-hydroxy aldehydes are Schiff base ligands that typically coordinate as a chelate in anO,N,O′-manner. Dinuclear complexes are normally observed, with the phenolate O atom acting as the bridging atom. The switchable protonation state of the tridentateN′-(2-hydroxybenzylidene)benzohydrazide (H2sabhz) ligand can lead to variations in the resulting supramolecular structure. The title compound, [Pb2(C14H10N2O2)2], was prepared by the reaction of [Pb(OAc)2]·3H2O (OAc is acetate) with the benzoylhydrazone derivative of salicylaldehyde,i.e.H2sabhz, in the presence of triethylamine in methanol. In the crystal structure, each PbIIatom of the dimer has an NO3coordination environment, with one sabhz ligand coordinating in anO,N,O′-manner and with the second sabhz ligand coordinatingviathe bridging phenolate O atom, since the dimers are located on a centre of inversion. It has been found that the dimers are connected by Pb...N interactions, resulting in a two-dimensional supramolecular network which shows the [32.52,3.53] net topology. Thes2electron pair of the PbIIion clearly influences the observed intermolecular interactions.

The hydrazone ligands 2-acetylpyridine benzoylhydrazone HL1 and 2,6-diacetylpyridinebis(benzoylhydrazone) H2L2 were reacted with Pb(SCN)2, affording [Pb(HL1)(µ-NCS)2] (1) and [Pb(H2L2)(SCN)2] (3), respectively. Recrystallization of 1 or 3 in DMF (or DMSO) produced [Pb(L1)(µ-SCN)] (2) and [Pb(HL2)(NCS)] (4), respectively. Compounds 1-4 were characterized by single crystal X-ray diffraction, Fourier transform infrared spectroscopy and elemental analysis. Compounds 1 and 3 were also characterized by thermogravimetry (with simultaneous differential scanning calorimetry), diffuse reflectance spectroscopy and powder X-ray diffraction. In the solid state, compounds 1, 3 and 4 have shown hydrogen bonds involving the amide hydrogen atoms. Both Pb···N(imine) tetrel bonds and π-stacking interactions were observed in 2 and 4. The thiocyanate/isothiocyanate ligands are responsible for the formation of chains due to Pb···S tetrel bonds in 1 and Pb···N, in 2.

The isophthaloylbis(N,N-diphenylthiourea) molecule (H2L ligand) reacts with CuI, CuII, MnIII, FeII, FeIII and CoII ions to form binuclear complexes with formula [M2(L-O,S)2] (M = CuII (1), NiII (2)) or [M2(L-O,S)3] (M = FeIII (4), CoIII (5)). In presence of dimethyl sulfoxide, [Mn2(L-O,S)2(dmso)2] (3) was successfully obtained and represents the first manganese complex with any thiourea derivative ligand. The ligand and the complexes were characterized by spectroscopic techniques and elemental analysis. Complexes 1, 3, 4 and 5 were structurally analyzed by single crystal X-ray diffraction data, confirming the O,S chelating coordination mode. The stoichiometries were confirmed by thermal analysis with formation of the corresponding metal oxides. The set of the performed analysis corroborated that some metal ions undergo oxidation or reduction to form stable 2:2 or 2:3 metal to ligand stoichiometric complexes with H2L.

Semicarbazones can exist in two tautomeric forms. In the solid state, they are found in the keto form. This work presents the synthesis, structures and spectroscopic characterization (IR and NMR spectroscopy) of four such compounds, namely the neutral molecule 4-phenyl-1-[phenyl(pyridin-2-yl)methylidene]semicarbazide, C19H16N4O, (I), abbreviated as HBzPyS, and three different hydrated salts, namely the chloride dihydrate, C19H17N4O+·Cl−·2H2O, (II), the nitrate dihydrate, C19H17N4O+·NO3 −·2H2O, (III), and the thiocyanate 2.5-hydrate, C19H17N4O+·SCN−·2.5H2O, (IV), of 2-[phenyl({[(phenylcarbamoyl)amino]imino})methyl]pyridinium, abbreviated as [H2BzPyS]+·X −·nH2O, with X = Cl− and n = 2 for (II), X = NO3 − and n = 2 for (III), and X = SCN− and n = 2.5 for (IV), showing the influence of the anionic form in the intermolecular interactions. Water molecules and counter-ions (chloride or nitrate) are involved in the formation of a two-dimensional arrangement by the establishment of hydrogen bonds with the N—H groups of the cation, stabilizing the E isomers in the solid state. The neutral HBzPyS molecule crystallized as the E isomer due to the existence of weak π–π interactions between pairs of molecules. The calculated IR spectrum of the hydrated [H2BzPyS]+ cation is in good agreement with the experimental results.

Reactions of 3,3,3′,3′-tetraethyl-1,1-isophthaloylbis(thiourea), H 2 L1a, with InCl 3 , Pb(acetate) 2 , [AuCl(PPh 3 )] and [CuCl(PPh 3 )] 4 gave complexes of the compositions [In 2 (L1a-κ O , S ) 3 ], [{Pb(L1a-κ O , S )} 2 ] ∞ , [{Au(PPh 3 )} 2 (L1a-κ S )] and [{Cu(L1a-κ O , S )} 2 ], respectively. The products have been studied spectroscopically and by single-crystal X-ray diffraction. Depending on the specific requirements of the metal ions used, complexes of completely different basic structures have been obtained: a binuclear complex with two octahedrally coordinated indium atoms, a polymeric lead compound with two differently coordinated Pb 2+ ions, a binuclear gold compound in which two {Au(PPh 3 )} + building blocks are connected by a L1a 2− ligand and a binuclear copper(II) complex with two cis-coordinated metal centers.