•Two products were obtained with the same reactants but different molar ratios.•The title two organic-inorganic hybrid compounds have different crystal structure.•The fluorescent spectra of the two organic-inorganic hybrid compounds were different.Two inorganic–organic hybrid compounds [(C7H18N2)6Pb7I26] (1) and [(C7H18N2)Pb2I6] (2) have been synthesized by reactions of 2-(2-aminoethyl)-1-methylpyrrolidine and lead iodide with 1: 1 and 1: 2 M ratios in concentrated HI aqueous. The single-crystal X-ray diffraction revealed that the inorganic component in compound 1 can be viewed as a wave-like 2D sheet built up from alternatively perovskite and non-perovskite structure types connected with corner-, edge- sharing octahedral [PbI6]; and that in complex 2 is a zigzag chain constructed with edge- sharing octahedral [PbI6]. In addition, both complexes showed fluorescent properties with complex 1 emitted green light at 545 nm and complex 2 emitted blue light at 467 nm.Reactions of 2-(2-aminoethyl)-1-methylpyrrolidine with lead iodide with 1:1 and 1:2 M ratios in concentrated HI aqueous led to a 2D wave-like sheet (1) and a 1D zigzag chain (2), both showed fluorescent properties.Download high-res image (309KB)Download full-size image

The reaction of manganese(II) halide MnCl2·4H2O and tris(2-aminoethyl)amine N(CH2CH2NH2)3 in the concentrated acid HCl at 65 °C resulted in the formation of an inorganic–organic hybrid complex: [(C6H22N4)2(H3O)(MnCl6)(MnCl5)(Cl)2]·3H2O (1) and a known byproduct [(C6H22N4)Cl4]·H2O. The analogue reactions between MnBr2·4H2O and N(CH2CH2NH2)3 in HBr acid gave a pure complex [(C6H22N4)2Br5](MnBr5) (2). Crystal structures revealed that Mn centers in 1 adopted trigonal bipyramidal and octahedral two geometries, while in 2 showed only trigonal bipyramidal geometry. Luminescent investigation exhibited complex 1 gave pink luminescence and complex 2 emitted yellow light in solid states, which were both directly originated from the coordinated geometries of Mn2+ ion.Two organic–inorganic hybrids obtained by reactions of MnX2 and tris(2-aminoethyl)amine in halide acids (HX, X = Cl, Br) gave pink and yellow emission when excited by 440 nm light.Download high-res image (63KB)Download full-size image

Reactions of two free N-heterocyclic carbenes (NHCs) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) and 1,3-dimesitylimidazol-2-yliden (IMes) with group VB transition metals MCl5 at low temperature gave a mono-NHC complex [(IPr)TaCl5] (1) and two bis-NHCs [(IMes)2MCl4][MCl6] (M = Ta, 2; =Nb, 3). Crystallographic studies revealed that the substitution effect plays an important role in the construction of these two different types of NHC complexes. Although mono-NHC complex 1 has been theoretically analyzed by F. Marchetti, complexes 2 and 3 represented the first examples of the structurally characterized bis-NHCs Ta(V) and Nb(V) complexes. In addition, complexes 1–3 showed catalytic efficiency in the cycloaddition between CO2 and propylene oxide to synthesize cyclic carbonates under mild conditions.

•Two tantalum complexes [(IMes:CO2)TaCl5] and [(IPr:CO2)2TaCl3][TaCl6]2 with high oxidation were obtained.•The crystal structures of the obtained tantalum complexes were discussed.•The catalytic properties of two complexes on the cycloaddition between CO2 and propylene oxide were investigated.Carboxylation of two free N-heterocyclic carbenes (NHCs) 1,3-dimesitylimidazol-2-yliden (IMes) and 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) with CO2 led to two adducts [IMes:CO2] and [IPr:CO2], which were further reacted with TaCl5 to afford the finial metal complexes [(IMes:CO2)TaCl5] (1) and [(IPr:CO2)2TaCl3][TaCl6]2 (2), respectively. NMR spectroscopy, elemental analysis and single crystal X-ray diffraction proved that the carboxylate groups were retained in complexes 1 and 2. Crystallography revealed that the metal centers in complexes 1 and 2 adopted the distorted octahedral and pentagonal bipyramidal geometries, respectively, in which complex 1 was constructed with one [IMes:CO2] adducts, while complex 2 with two [IPr:CO2] adducts. In addition, the catalytic properties of complexes 1–2 on the cycloaddition between CO2 and propylene oxide to synthesize cyclic carbonate at the mild condition were investigated.Two imidazolylidene carboxylates [IMes:CO2] and [IPr:CO2], which were obtained by combination of CO2 with N-heterocyclic carbenes, were reacted with VB group metal TaCl5 to give a monomeric complex [(IMes:CO2)TaCl5] (1) and a dimeric complex [(IPr:CO2)2TaCl3][TaCl6]2 (2) with high oxidation of metal.

Reaction of a heptadentate ligand (H2LI) and a hexadentate ligand (H2LII) with three equivalents of Cu(ClO4)2·6H2O in methanol under basic conditions afforded a hexanuclear cluster [Cu6(LI)2(OH)4](ClO4)4·2DMF·3Et2O (1) and a nonanuclear cluster [(Cu9(LII)3(OH)7)](ClO4)5·0.25CH3OH·1.15H2O (2), respectively, where H2LI is 2,2′-(((pyridine-2,6-diylbis(methylene))bis((pyridin-2-ylmethyl)azanediyl))bis(methylene))diphenol and H2LII 2,2′-((((5-methyl-1,3-phenylene)bis(methylene))bis((pyridin-2-ylmethyl)azane-diyl))bis(methylene))bis(4-methylphenol). The structures of both clusters in their solid states have been determined by X-ray crystallography. Their magnetic susceptibilities reveal that both clusters are antiferromagnetic due to the coupling between the copper centers in the clusters. NMR spectroscopic analysis, conductivity measurements and ESI-MS analysis suggest that the clusters retain their structural integrities in solution. Both clusters show catalytic activity towards the hydroxylation of benzene into phenol with hydrogen peroxide (H2O2) as an oxidant at 80 °C in aqueous acetonitrile. The conversion rate is about 20% and their TON/TOF are 564/188 and 905/302 for clusters 1 and 2, respectively.

•Two multidentate ligands containing phenolate, triazolyl and pyridinyl groups were synthesized by click reactions.•The synthesis and crystal structures of three dinuclear Cu2+ and Fe3+ complexes based on the ligands were discussed.•The structure differences in the three complexes were revealed by the different coordinating donors of two ligands.•The electrochemistry of complexes 1–3 was investigated.Two multidentate ligands 2,2′-(1,1′-(pyridine-2,6-diylbis(methylene))bis(1H-1,2,3-triazole-4,1-diyl))bis(methylene)bis((pyridin-2-ylmethyl)azanediyl)bis(methylene)diphenol (H2LI) and N,N′-((1,1′-(pyridine-2,6-diylbis(methylene))bis(1H-1,2,3-triazole-4,1-diyl))bis(methylene))bis(1-(pyridin-2-yl)-N-(pyridin-2-ylmethyl)methanamine) (LII) containing triazolyl, phenolate and pyridinyl groups were prepared by click reaction between diazide and terminal alkynes in the presence of catalyst CuI. Both ligands were reacted with Cu2+ and Fe3+ salts to give three dinuclear complexes [LICu2](BPh4)2·2DMF (1), [LII(DMF)2Cu2](ClO4)4·H2O (2) and [LII(FeCl2)2](PF6)2 (3). All complexes were characterized by IR, UV–Vis spectra and element analysis. X-ray analysis revealed that the Cu2+ centers in complexes 1 and 2 adopted the distorted trigonal bipyramidal geometry, and the Fe3+ center in complex 3 chose an octahedral geometry. In addition, the electrochemistry of complexes 1–3 was investigated.Graphical abstractMultidentate ligands H2LI and LII containing triazolyl, phenolate and pyridinyl groups were reacted with Cu(ClO4)2 to give dinuclear complexes [LICu2](BPh4)2 (1) and [LII(DMF)2Cu2](ClO4)4 (2).

A multidentate ligand, namely N,N-bis[[1-(phenylmethyl)-1H-1,2,3-triazol-4-yl]methyl]-2-pyridinemethaneamine (L), was synthesized through a click reaction of N,N-di-2-propyn-1-yl-2-pyridinemethanamine with benzyl azide in the presence of CuI catalyst. Treatment of L with CuCl2 or Fe(NCS)2 gave the complexes [CuLCl2]·EtOH (1) and [FeL(NCS)2]·MeCN (2). Single-crystal X-ray studies show that in 1, the Cu(II) center has slightly distorted square pyramidal geometry resulting from the coordination of one pyridinyl nitrogen atom, one tertiary amine nitrogen atom, one triazole nitrogen atom, and two chloride atoms; in 2, the Fe(II) center has distorted octahedral geometry, coordinated by six nitrogen atoms; two each from NCS− groups and triazole rings, one from a pyridinyl ring, and one from tertiary amine nitrogen. In addition, complexes 1 and 2 were characterized by spectroscopic and electrochemical methods.

Two Hg(II) complexes [HgL′(ClO4)2] (1) and [HgL(ClO4)]ClO4 (2) derived from the macrocyclic ligands, 4-(pyridin-2-ylmethyl)-1,7-dithia-4,10-diazacyclododecane (L′) and 7-(pyridin-2-ylmethyl)-1,4,10-trithia-7,13-diazacyclopentadecane (L), have been crystallographically characterised. Ligand L and its Hg(II) complex were isolated unexpectedly, and a possible formation pathway of the ligand is proposed. By including weakly bound O atoms from the perchlorate ions, the Hg atoms in both complexes are seven-coordinate and possess capped trigonal prismatic geometries. These uncommon structures for Hg(II) complexes were achieved mainly by the relatively large size of the metal ion and the steric effect from the macrocycles. In both complexes, strong hydrogen bonding between the amine hydrogen atom and a perchlorate ion was observed. For complex 1, the interaction is N(3)–H(15)···O(8) at 2.08(12) Å where O(8) is of the same anion as one of the coordinated O atoms; in complex 2, a similar hydrogen bond, N(7)–H(7)···O(32), with a distance of 2.25 Å, is formed to the coordinated anion, but the second anion remains discrete.Two Hg(II) complexes [HgL′(ClO4)2] (1) (left) and [HgL(ClO4)]ClO4 (2) (right), with distorted capped trigonal prismatic geometries, were isolated by reacting Hg(ClO4)2·3H2O with the two macrocyclic ligands, 4-(pyridin-2-ylmethyl)-1,7-dithia-4,10-diazacyclododecane (L′) and 7-(pyridin-2-ylmethyl)-1,4,10-trithia-7,13-diazacyclopentadecane (L). The steric tension imposed by the macrocycle and the size of the Hg(II) centre presumably lead to the geometry observed.