Cadmium(II) diallyldithiocarbamato complexes with 2,2′-bipyridine and 1,10-phenanthroline: spectroscopic and crystal structure analysis

Complexes of Cd(II) with diallyldithiocarbamato (hereafter denoted aldtc) and 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) are discussed. Derivatives of general formula [Cd(aldtc)₂(NN)] [NN = bipy, 1 and phen, 2] have been obtained by direct reaction between Cd(NO₃)₂ and a 2 : 1 molar ratio of aldtc and NN. The new complexes have been characterized by IR, ¹H, and ¹³C NMR spectroscopy. Their single crystal structures were also determined. Compounds 1 and 2 have severely distorted octahedral coordination around cadmium, defined by an N₂S₄ donor set. The structure of 1 is isomorphous with the recently reported zinc analogue. The crystal packing of 1 shows different non-classical intermolecular interactions represented in both hydrophilic (π)C–H ··· S and hydrophobic (allyl)C–H ··· C(π) intermolecular interactions. Such interactions result in a chain arrangement of molecules along the crystallographic c-axis. These chains are further connected via π ··· π stacking along with (π)C–H ··· S parallel to b leading to an overall crystal packing that can be regarded as layers of complexes along the bc plane. Molecules in the crystal structure of 2 are arranged into infinite chains, down the b-axis, that are connected by aryl ··· aryl stacking. The chains are further connected to each other in a and c directions via (allyl)C–H ··· S interactions.     

Supramolecular structures of CdX2-containing coordination compounds constructed by C–H ··· X synthons

Three CdX₂-containing (X = Cl, Br) compounds [CdBr₂(Him)₂] _n (Him = imidazole) (1), [CdCl₂(2,2′-bipy)] _n (2,2′-bipy = 2,2′-bipyridine) (2), and [CdCl₂(phen)] (phen = phenanthroline) (3) have been synthesized through hydrothermal technique. Compound 1 adopts 1-D coordination chain, which is connected to form a 3-D supramolecular network by inter-chain N–H ··· Br and C–H ··· Br hydrogen bonds. Compound 2 also adopts 1-D coordination chain, which is connected to form 3-D supramolecular network by intra- and inter-chain C–H ··· Cl hydrogen bonds; 3 is discrete, linked to form 2-D supramolecular sheets by intra- and inter-molecular C–H ··· Cl hydrogen bonds. The different volume and coordination ability of organic ligands result in the different coordination structure and supramolecular synthons. All these compounds exhibit strong fluorescence emissions at room temperature.     

Crystallographic and theoretical studies of 4,4′-dimethyl-7,7′-bi([1,2,5]thiadiazolo[3,4-b]pyridylidene)–chloranilic acid (1/1) with intermolecular O–H···N hydrogen bonds and S···O heteroatom interactions

Abstract  The molecular and crystal structure of a 1:1 co-crystal of 4,4′-dimethyl-7,7′-bi([1,2,5]thiadiazolo[3,4-b]pyridylidene)–chloranilic acid, (1), has been determined by X-ray diffraction at the monoclinic space group P2₁/c with cell parameters of a = 8.422(6), b = 7.343(4), c = 16.112(7) ?, β = 104.988(8)°, V = 962.5(10) ?³ and Z = 2. In the crystal structure, two components connect via the intermolecular O–H···N hydrogen bonds [2.804(4) ?] and S···O heteroatom interaction [2.945(3) ?] with R ₂ ²(7) couplings to form a unique and infinite one-dimensional supramolecular tape structure. The calculations of (1) at the HF/6-31G(d), MP2/6-31G(d), and B3LYP/6-31G(d) levels can almost reproduce X-ray geometry. In addition, the distances of the intermolecular O–H···N and S···O interactions by MP2/6-31G(d) and B3LYP/6-31G(d) levels agree well with those in the crystal. The calculated binding energies corrected BSSE and ZPE are −4.487 (HF), −7.473 (MP2), and −5.640 (B3LYP) kcal/mol. The results suggest that the complex (1) is very stable and the dispersion interaction is significantly important for the attractive intermolecular interaction in (1). The NBO analysis has revealed that the n(N) → σ*(O–H) interaction gives the strongest stabilization to the system and the major interaction for the intermolecular S···O contact is n(O) → σ*(S–N). Index Abstract  In the crystal structure of the title compound, the molecules are linked by intermolecular O–H···N hydrogen bonds and short S···O heteroatom interactions with R ₂ ²(7) couplings to construct a unique and infinite one-dimensional supramolecular tape structure.      

A linear chain polymer {Ag2[S2P(OC2H5)2]2(bix)} n with multiple emission and red luminescence

The linear chain {Ag₂[S₂P(OC₂H₅)₂]₂(bix)} _n 1 was obtained from reaction of Ag[S₂P(OC₂H₅)₂] with bix (bix =?1,4-bis(imidazole-l-ylmethyl)benzene). Compound 1 consists of a dinuclear module with intramolecular Ag ··· Ag interactions (2.9842(5) Å). This interaction shows a profound influence on the observed multiple luminescence emissions for 1. Crystal data for 1 at 293(2) K: Space group P 1, a =?9.7158(1), b =?9.8273(2), c =?10.0758(2) Å, α =?70.989(1), β =?89.308(1), γ =?63.868(1)°, V =?806.75(2) ų, Z =?1, R ₁ =?0.0294.     

Three new homoleptic nickel(II) 1,1-dithiocarbamate complexes: synthesis,structure, electrical conductivity and DFT study

Abstract

Three new homoleptic complexes of nickel having the formula [Ni(L1)₂] [L1?=?C₁₄H₁₄N₁O₂S₂^-, N-(4-methoxybenzyl)(furfuryl)methane dithiocarbamate] (1), [Ni(L2)₂] [L2?=?C₁₇H₁₈N₁O₂S₂^–, N-bis(4-methoxybenzyl)methane dithiocarbamate] (2) and [Ni(L3)₂] [L3?=?C₁₉H₂₁N₁O₁S₂^-, N-(4-isopropylbenzyl)(4-methoxybenzyl)methane dithiocarbamate] (3), have been designed, synthesized, and characterized by elemental analysis, IR, ¹H and ¹³C NMR and UV-visible absorption spectra showing that all complexes having analogous geometry and coordination number. The molecular structure of 2 is confirmed by single-crystal X-ray crystallography, which indicates that +2 charges on the metal ion (Ni²⁺) are balanced by dithiocarbamate anion. The X-ray analysis for 2 reveals a distorted square planar geometry around Ni²⁺ ion. Both C?–?H···S and intermolecular C–H···Ni interactions are the only artifact for the resulting Ni-dithiocarbamate architecture in 2. The electrical conductivity measurement between temperatures range of 303–393 K reflects that all complexes exhibit weak semiconducting behavior. Powder XRD, EDAX, and SEM spectra confirm the formation of NiS as thermal decomposition product in 1–3. The crystalline size of samples 1–3 was found to be 20.31?nm, 20.97?nm, and 20.39?nm, respectively.     

Modification of supramolecular assemblies based on C4H7(CH3)Te heterocycle and cooperative participation of intermolecular I···I, Te···I, Te···O secondary bonds; C(sp3)–H···O and C(sp2)–H···O hydrogen bonds

2-Methyl-1,1-dicarboxylato-1-telluracyclopentanes C₄H₇(CH₃)Te(OCOR)₂ (R=OCO, C₆H₅, 4-NO₂C₆H₄, 3,5-(NO₂)₂C₆H₃, C₆H₅CH=CH, 4-OCH₃C₆H₄) (2–7) were synthesised from the reactions of 2-methyl-1,1-diiodo-1-telluracyclopentane (1) and corresponding silver salts and characterised by (IR &¹HNMR) spectroscopy. The structures of C₄H₇(CH₃)TeI₂ (1), C₄H₇(CH₃)Te(OCOC₆H₅)₂ (3) and C₄H₇(CH₃)Te(4-NO₂C₆H₄OCO)₂ (4) were established by single crystal X-ray diffraction studies. The structures of 1, 3 & 4 (the immediate environment about tellurium is that of distorted trigonal bipyramidal geometry with a stereochemically active electron lone pair) are described in the context of their ability to generate intermolecular I···I, Te···I, Te···O secondary bonds; C(sp³)–H···O and C(sp²)–H···O hydrogen bonds leading to the formation of polymeric, tetrameric and trimeric supramolecular assemblies. The modification of supramolecular assembly present in the precursor 1 is demonstrated and the cooperative participation of C(sp²)–H···O & C(sp³)–H···O hydrogen bonds, probably, helpful in strengthening the supramolecular assembly is discussed.

Synthesis,structures, and properties of lead(II) and cobalt(II) metal-organic frameworks based on a flexible benzophenone-2,4′-dicarboxylic acid (H2bpdc)

Two new coordination polymers, [Pb(bpdc)] _n (1) and [Co(bpdc)(phen)] _n (2) [H₂bpdc?=?benzophenone-2,4′-dicarboxylic acid, phen?=?1,10-phenanthroline], have been synthesized and structurally characterized. Hydrogen bonding and π?···?π stacking extend 1 and 2 into 3-D supramolecular architectures, where 1 exhibits a 3-D framework with 1-D hairpin-like helicates based on Pb–O covalent bonds and 2 displays a 3-D network with 1-D zipper-like chains based on Co–O and Co–N covalent bonds. The FT-IR spectra, PXRD and TG analyses are discussed for 1 and 2. Fluorescence spectra and luminescent lifetime are studied for 1.     

Zinc(II) complexes of 4,4-oxybis(benzoate) and 2-propyl-4,5-imidazoledicarboxylic acid with bipyridine

The reactions of dicarboxylic acids, such as 4,4-oxybis(benzoic acid) [H₂oba] and 2-propyl-4,5-imidazoledicarboxylate [H₃pimdc], under hydrothermal conditions in the presence of an appropriate zinc salt yield two mononuclear complexes, which are characterized by elemental analysis, infrared spectrum, electrochemical analysis, thermal analysis, and X-ray crystal diffraction. Complex 1, [Zn(Hoba)₂(4,4′-bpy)₂], forms a 2-D supramolecular layer like rhombus via hydrogen bonds (O–H?···?N). Complex 2, [Zn(H₂pimdc)₂(2,2′-bpy)]?·?H₂O, forms a zig-zag chain via multiple hydrogen bonds and C–H?···?π interactions. The moderate hydrogen-bond interactions in 1 and 2 play an important role for structural stability. The electrochemical analyses of 1 and 2 reveal electron transfer of 1 is reversible and 2 is quasi-reversible.     

Unusual coordination features and self-assembly of a crown ether complex [Na2(2,3-naphtho-15-crown-5)2(NO3)][Cu(NO3)3(H2O)]

A novel supramolecular complex, [Na₂(2,3-naphtho-15-crown-5)₂(NO₃)][Cu(NO₃)₃(H₂O)] (1), has been prepared and characterized by X-ray single crystal diffraction. The complex crystallizes in the triclinic system, space group Pī, with a?=?11.233(6), b?=?13.342(7), c?=?16.601(8)?Å, α?=?89.836(7), β?=?79.132(8), γ?=?66.545(7)°, V?=?2234(2)?ų, Z?=?2 and final R ₁(wR ₂)?=?0.0467(0.1164). Novel coordination features and supramolecular architectures are found in the solid state of 1. Two [Na(2,3-naphtho-15-crown-5)]⁺ cations containing two different sodium coordination numbers (six and seven) are bridged by a tridentate nitrate group, to form a larger complex cation, [Na₂(2,3-naphtho-15-crown-5)₂(NO₃)], which is assembled into a novel 1D zigzag chain-like structure through aromatic C–H?···?π interactions.     

C–H···Onitrate synthon assisted molecular assembly of hydrogen bonded Ni(II) and Cu(II) complexes

Two Schiff base metal complexes [Cu–SPETN·NO₃ (1) and Ni–SPETN·NO₃ (2) [SPETN?=?2,2′-[propane,1,3-diylbis(nitrilomethyldyne)pyridyl,phenolate]] with hydrogen bonding groups have been synthesized and characterized by single-crystal X-ray diffraction. In both of the compounds nitrates occupy a crystallographic general position. In 1 the lattice nitrates are on the 2₁ screw axis while in 2 they are at the crystallographic inversion center. C–H···O_nitrate synthons (formed by the nitrate anions and peripheral hydrogen bonding groups of the metal complexes) are non-covalent building blocks in molecular-assembly and packing of the cationic Schiff base metal complexes (M?=?Ni²⁺, Cu²⁺), resulting in 2-D hydrogen bonded networks. The Cu···Cu non-bonding contact in 1 is 3.268?Å while the Ni–Ni bonding distance in 2 is 3.437?Å.     

The first C(O)NHP(O)-based phosphoric triamide structure with an N‒H···π hydrogen bonding: A combination of X-ray crystallography and theoretical study to evaluate the strength of hydrogen bonds

The hydrogen bond pattern of N-(4-methoxybenzoyl)-N′,N″-bis(4-methylbenzyl)-phosphoric triamide, C₂₄H₂₈N₃O₃P, (I), was investigated. In the crystal structure, the molecules are aggregated through N_CP―H···O═P and N_P―H···O═C hydrogen bonds in a one-dimensional arrangement parallel to the c axis (N_CP is the nitrogen atom in the C(O)NHP(O) segment and N_P stands for the two other nitrogen atoms bonded to the P atom). There is also a novel N_P?H···π hydrogen bond in the crystal which extends the aggregation of the molecules to a two-dimensional array parallel to the bc plane. A Cambridge Structural Database (CSD, version 5.37, Feb 2016) analysis shows that the N―H···π hydrogen bond was not observed in any of 156 [RC(O)NH]P(O)[NR¹R² Allen, F. H.; Taylor, R. Chem. Soc. Rev. 2004, 33, 463-475.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]]₂ (R¹ ≠ H, R² = H or ≠ H) phosphoric triamide structures reported so far. The theoretical calculations at the B3LYP/6-311G^** level of theory (DFT, AIM, and NBO) were performed to evaluate the strengths of N_CP―H···O═P, N_P―H···O═C and N_P―H···π hydrogen bonds, considering two-aggregate molecular assemblies containing these hydrogen bonds. The calculations on the title compound suggest that the intermolecular N_CP―H···O═P hydrogen bond is stronger than N_P―H···O═C and N_P―H···π interactions. The hydrogen bond strength was investigated by NBO, topological analysis, geometry calculation, Hirshfeld surface analysis and experimental spectroscopic results, which are in agreement with each other.     

Syntheses and crystal structures of triorganotin(IV) complexes based on mixed ligands of 2,4,5-trifluoro-3-methoxybenzoic acid and 4,4′-bipy

Four new complexes have been synthesized based on the 2,4,5-trifluoro-3-methoxybenzoic acid and 4,4′-bipy of the type [R₃Sn(OOCC₆HF₃OCH₃)]₂·(4,4′-bpy). All complexes were characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR spectra analyses. Complexes 1 and 4 were also characterized by X-ray crystallography. Crystal structures of 1 and 4 show that the coordination number of tin atom is five and the 2D network is connected by intermolecular C–H···O interactions.     

X-ray crystal structure,spectral and magnetic properties of end-to-end di-μ-thiocyanatobis(imidazole)M(II) polymeric complexes (M=Co,Mn): supramolecular network structure based on N–H ··· S hydrogen bonding and π ··· π stacking

Two isomorphous one-dimensional chain complexes Co(NCS)₂(Him)₂ (1) and Mn(NCS)₂(Him)₂ (2) (Him?=?imidazole) have been prepared and characterized structurally. Both 1 and 2 crystallize in the monoclinic system, space group P2₁/n, and the structures consist of one-dimensional polymeric chains in which metal ions are bridged by two thiocyanate groups bonding in end-to-end fashion. Both 1 and 2 exhibit two-dimensional sheet structures with N–H?···?S hydrogen bonds and three-dimensional supramolecular network structure with π?···?π stacking interactions. IR spectra indicate the presence of bridging thiocyanate groups in both 1 and 2, confirmed by their structures. The variable temperature magnetic susceptibility, measured in the 2–300?K range, indicates weak antiferromagnetic exchange interactions in complex 2.     

Supramolecular architectures with ladder and lamellar topologies using metal-ligand coordination units via C–H···Cl and O–H···Cl hydrogen bonding

New Mn^II/Cu^II/Zn^II complexes [(L¹)MnCl₂] (1), [(L²)CuCl₂]·0.5H₂O (2) and [(L²)ZnCl(H₂O)][ClO₄] (3), containing (2-pyridyl)alkylamine ligands, N-methyl-N,N-bis(2-pyridylmethyl)amine (L¹) and methyl[2-(2-pyridyl)ethyl](2-pyridylmethyl)amine (L²), have been prepared and characterized, including X-ray crystallography. The most striking feature of the structures of these complexes is the formation of molecular ladder and lamellar topology through the crystal packing arrangement, determined by both strong O–H···Cl and weak (however, multiple) C–H···Cl hydrogen-bonding interactions, to maintain the neutral/cationic metal-ligand coordination units linked to each other. In 3, additional secondary interactions are observed involving coordinated solvent and the counter-ion. The results presented here demonstrate that (i) the choice of organic ligands to provide flexibility and inherent potential to participate in hydrogen-bonding interactions, (ii) the coordination geometry preferences of metal ions, (iii) the number of metal-bound chloride ion and (iv) the presence of solvent/counter-anion have a great influence on supramolecular network topology.     

Anion-driven Ag(I) coordination architectures: structural diversity and photoluminescence behaviors

To observe anion impact on structural diversity of coordination architectures, three 1-D Ag(I) complexes with distinct features have been prepared, {[Ag(bpbib)₂(NO₃)]·C₃NH₉O)}_n (1), [Ag₂(bpbib)₂·(BF₄)₂]_n (2), and [Ag₂(bpbib)₂·(ClO₄)₂]_n (3), by the reactions of 4,4′-bis((2-(pyridin-2-yl)-¹H-benzo[d]imidazol-1-yl)methyl)biphenyl (bpbib) with Ag(I) salts. Complex 1 is a 1-D helical chain, whereas 2 and 3 bear ligand-unsupported Ag(I)···Ag(I) interaction-directed 1-D structural motif, with synergetic working of flexible organic linker and anions. All complexes exhibit strong triplet state emission at cryogenic temperatures, which profits from the reduction of nonradiative transitions.     

Zinc(II) and cadmium(II) complexes of Schiff bases derived from amino acids and pyridine-3-carboxaldehyde: synthesis,crystal structures,and fluorescence

Two d¹⁰ Schiff-base complexes, Zn₂(L₁)₂(H₂O)₆ ? SO₄ (1) and Cd(L₂)₂(H₂O)₄ (2) [HL₁ = 3-((pyrid-3-yl)-methylene)aminobenzoic acid; HL₂ = 4-((pyrid-3-yl)-methylene)aminobenzoic acid], have been synthesized and structurally characterized by elemental analyses, FT-IR spectra, and thermal studies, as well as single crystal X-ray diffraction. Complex 1 is a dinuclear macrocyclic structure with 22-membered rings and is assembled into a 3-D sandwich supramolecular network motif through H-bonding interactions; 2 is a mononuclear structure and is interlinked through H-bonding and π ··· π stacking contacts to generate another 3-D supramolecular network. Furthermore, fluorescent properties of the two complexes are also reported.     

Syntheses and structural characterization of organotin(IV) complexes derived from reaction of 2,3-diphenylpropionic acid and various alkyltin salts

Five new organotin(IV) complexes, [(R₃Sn)(O₂C₁₅H₁₃)] _n (R?=?Me: 1; nBu: 2), [RSn(O)(O₂C₁₅H₁₃)]₆ (R?=?Ph: 3), [(R₂Sn)₂(O₂C₁₅H₁₃)₂(μ ₃-O)]₂ (R?=?Me: 4), and [(R₂Sn)(O₂C₁₅H₁₃)₂] (R?=?nBu: 5), have been prepared by the reaction of 2,3-diphenylpropionic acid and the corresponding organotin chloride with sodium ethoxide in methanol. All the complexes were characterized by elemental analysis, FT-IR, NMR (¹H, ¹³C, ¹¹⁹Sn) spectroscopy, TGA, and X-ray crystallography. The structural analyses reveal that 1 and 2 are 1-D infinite polymeric chains with Sn in syn–anti conformation. Complex 3 has a drum structure with six Sn centers. Complex 4 has a supramolecular chain-like ladder through weak intermolecular Sn?···?O interactions. Complex 5 is a monomer, connected into a 1-D polymer through intermolecular C–H?···?O interactions. Complexes 1 and 5 crystallize in the orthorhombic space groups P212121 and P21212, which are chiral space groups.     

Binuclear paddle-wheel platinum(II) and platinum(III) complexes containing 4-methyl-4H-1,2,4-triazole-3-thiol ligand: Synthesis,X-ray studies,and spectroscopic characterization

The complex [Pt₂(μ-mtrzt)₄(mtrzt)₂] (1) was synthesized from the reaction of a mixture of 4-methyl-4H-1,2,4-triazole-3-thiol (Hmtrzt) and ethylenediamine (en) with K₂PtCl₄ in CH₃OH/H₂O (2:1) as solvent. The complex [Pt₂(μ-mtrzt)₄] (2) was synthesized by the same procedure as described for preparation of complex 1 but in the absence of ethylenediamine. Both complexes were characterized by elemental analysis, IR,¹H NMR,¹³C{¹H}NMR, UV-Vis, as well as luminescence spectroscopy and their structures were analyzed by single-crystal X-ray diffraction method. The X-ray structure determinations show that complexes of 1 and 2 have binuclear structures in a paddle-wheel fashion with Pt-Pt distances of 2.6628(7) and 2.7977(16)Å, respectively. In complex 1, each platinum(III) atom has a distorted octahedral coordination geometry with the sulfur atom and the second platinum subunit in axial positions and two nitrogen and two sulfur atoms in equatorial positions. Also, in complex 2, each platinum(II) atom has a distorted square-pyramidal coordination geometry with the second platinum subunit in axial position and two nitrogen and two sulfur atoms in equatorial positions. In addition, intermolecular C?H···N and C?H···S hydrogen bonds in 1 and 2 as well as intermolecular anagostic C?H···Pt and C?H···π interactions in 2 are effective in the stabilization of the crystal packing of these complexes.     

Supramolecular inclusion of a pillared double-layered host by an anion-directed second-sphere coordination

In this paper, we have illustrated the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with varieties of guest molecules. A flexible molecule N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine (L1) bearing doubly protonated H-bond donors was designed, capable of forming N–H…Cl hydrogen bonds with a crystallographically unique chloride anion, to construct an anion-directed ligand. The pillared double-layered host framework was constructed by an anion-directed ligand and primary coordination sphere [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interactions. A variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of novel supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2).

We have presented herein the utilisation of a second-sphere coordination approach to construct supramolecular inclusion solids with a variety of guest molecules. A novel type of a pillared double-layered host framework was constructed by a second-sphere coordination between the anion-directed ligand (L1 = N,N,N′,N′-tetra-p-methylbenzyl-ethylenediamine) and [CoCl₄]^2 ?  through weak C–H…Cl hydrogen-bonding interaction, and a variety of guest molecules, such as p-anisaldehyde, 1,4-dimethoxy-2,5-bis(methoxymethyl)benzene, can be included, leading to the formation of supramolecular inclusion solids: [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₈H₈O₂]·0.25[CH₃OH] (1) and [L1]·4[H]⁺·[CoCl₄]^2 ? ·2Cl^? ·1.5[C₁₂H₂₀O₄]·0.5[CH₃OH] (2)