Investigation of putative arene-C-H···π(quasi-chelate ring) interactions in copper(I) crystal structures

Bis(μ-iodo)-tetrakis(O-methyl N-phenylthiocarbamate)-tetraiodo-dibismuth

In order to investigate the coordination chemistry of O-alkyl N-aryl thiocarbamate ligands, BiI3 was reacted with two equivalents of MeOC(=S)N(H)Ph in MeCN solution to afford the dinuclear title compound complexes [{I2Bi(μ2-I)2BiI2}{κ1-MeOC(=S)N(H)Ph}4] 1. Compound 1 was characterized by IR, UV and NMR spectroscopy, the formation of a dinuclear framework is ascertained by a single-crystal X-ray diffraction study performed at 100 K.

Ferrocene-Functionalized Dithiocarbamate Zinc(II) Complexes as Efficient Bifunctional Catalysts for the One-Pot Synthesis of Chromene and Imidazopyrimidine Derivatives via Knoevenagel Condensation Reaction

Four new mononuclear/coordination polymeric (CP) zinc(II) complexes (1-4) of ferrocenyl/pyridyl-functionalized dithiocarbamate ligands, N-ferrocenylmethyl-N-butyl dithiocarbamate (L1), N-ferrocenylmethyl-N-ethylmorpholine dithiocarbamate (L2), N-ferrocenylmethyl-N-2-(diethylamino)ethylamine dithiocarbamate (L3), and N-4-methoxybenzyl-N-3-methylpyridyl dithiocarbamate (L4), have been synthesized and characterized by elemental analyses, IR, UV-vis, and ¹H and ¹³C{¹H} NMR spectroscopic techniques. The solid-state structures of complexes 1, 3, and 4 have been determined by single-crystal X-ray crystallography as well as powder X-ray diffraction. Single-crystal X-ray crystallography revealed a monomeric structure for complex 1 but 1D polymeric structures for complexes 3 and 4. In all complexes, dithiocarbamate ligands are bonded to the Zn(II) metal ion in a S^S chelating mode, and in the CPs, N atoms on the 2-(diethylamino)ethylamine and 3-pyridyl functionalities in the ligands on the neighboring molecules are also bonded to metal centers, leading to the formation of either a discrete tetrahedral molecule in 1 or 1D CP structures in 3 and 4. The Zn(II) metal centers in the polymeric structures exhibited either square-pyramidal or octahedral geometries. The supramolecular structures in these complexes are sustained via C-H···π (ZnCS₂, chelate; 3 and 4), C-H···π, and H···H interactions. The catalytic performances of complexes have also been assessed in the Knoevenagel condensation and one-pot multicomponent reactions. Catalysis results showed that the CP 3 acts as a heterogeneous bifunctional catalyst with excellent transformation efficiency at low catalyst loading.

Crystal structure of chlorido-(O-ethyl phenylcarbamothioamide-κS)-bis(triphenylphosphane-κP)-silver(I), C45H41AgClNOP2S

C45H41AgClNOP2S, monoclinic, P21/c (no. 14), a = 10.1930(3) Å, b = 18.3087(6) Å, c = 21.3088(6) Å, β = 94.516(3)°, V = 3964.3(2) Å3, Z = 4, R gt(F) = 0.0353, wR ref(F 2) = 0.0810, T = 100(2) K.

Crystal structure of chlorido-(O-methyl phenylcarbamothioamide-κS)-bis(triphenylphosphane-κP)silver(I), C44H39AgClNOP2S

C44H39AgClNOP2S, triclinic, P1̄ (no. 2), a = 10.2520(3) Å, b = 13.2252(4) Å, c = 14.9378(3) Å, α = 78.424(2)°, β = 78.388(2)°, γ = 84.534(3)°, V = 1940.35(9) Å3, Z = 2, R gt(F) = 0.0382, wR ref(F 2) = 0.0807, T = 100(2) K.

Effect of Substituents on the Crystal Structures, Optical Properties, and Catalytic Activity of Homoleptic Zn(II) and Cd(II) β-oxodithioester Complexes

Five novel zinc(II) and cadmium(II) β-oxodithioester complexes, [Zn(L1)₂] (1), [Zn(L2)₂]_n (2), [Zn(L3)₂]_n (3) [Cd(L1)₂]_n (4), [Cd(L2)₂]_n (5), with β-oxodithioester ligands, where L1 = 3-(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-1-olate, L2 = 3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-olate, and L3 = 3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-olate, were synthesized and characterized by elemental analysis, IR, UV-vis, and NMR spectroscopy (¹H and ¹³C{¹H}). The solid-state structures of all complexes were ascertained by single-crystal X-ray crystallography. The β-oxodithioester ligands are bonded to Zn(II)/Cd(II) metal ions in an O^∧S and N chelating/chelating-bridging fashion leading to the formation of 1D (in 2-4) and 2D (in 5) coordination polymeric structures, but complex 1 was obtained as a discrete tetrahedral molecule. Complex 4 crystallizes in the C2 chiral space group and has been studied using circular dichroism (CD) spectroscopy. The multidimensional assemblies in these complexes are stabilized by many important noncovalent C-H···π (ZnOSC₃, chelate), π···π, C-H···π, and H···H interactions. The catalytic activities of 1-5 in reactions involving C-C and C-O bond formation have been studied, and the results indicated that complex 3 can be efficiently utilized as a heterogeneous bifunctional catalyst for the Knoevenagel condensation and multicomponent reactions to develop biologically important organic molecules. The luminescent properties of complexes were also studied. Interestingly, zinc complexes 1-3 showed strong lumniscent emission in the solid state, whereas cadmium complexes 4 and 5 exhibited bright luminescent emission in the solution phase. The semiconducting behavior of the complexes was studied by solid-state diffuse reflectance spectra (DRS), which showed optical band gaps in the range of 2.49-2.62 eV.

4-[(1E)-({[(Benzyl-sulfan-yl)methane-thio-yl]amino}-imino)-meth-yl]benzene-1,3-diol chloro-form hemisolvate: crystal structure, Hirshfeld surface analysis and computational study

The title hydrazine carbodi-thio-ate chloro-form hemisolvate, 2C15H14N2O2S2·CHCl3, comprises two independent hydrazine carbodi-thio-ate mol-ecules, A and B, and a chloro-form mol-ecule; the latter is statistically disordered about its mol-ecular threefold axis. The common features of the organic mol-ecules include an almost planar, central CN2S2 chromophore [r.m.s. deviation = 0.0203 Å (A) and 0.0080 Å (B)], an E configuration about the imine bond and an intra-molecular hydroxyl-O-H⋯N(imine) hydrogen bond. The major conformational difference between the mol-ecules is seen in the relative dispositions of the phenyl rings as indicated by the values of the dihedral angles between the central plane and phenyl ring of 71.21 (6)° (A) and 54.73 (7)° (B). Finally, a difference is seen in the disposition of the outer hydroxyl-H atoms, having opposite relative orientations. In the calculated gas-phase structure, the entire mol-ecule is planar with the exception of the perpendicular phenyl ring. In the mol-ecular packing, the A and B mol-ecules assemble into a two-mol-ecule aggregate via N-H⋯S hydrogen bonds and eight-membered {⋯HNCS}2 synthons. The dimeric assemblies are connected into supra-molecular chains via hydroxyl-O-H⋯O(hydrox-yl) hydrogen bonds and these are linked into a double-chain through hy-droxy-O-H⋯π(phen-yl) inter-actions. The double-chains are connected into a three-dimensional architecture through phenyl-C-H⋯O(hydrox-yl) and phenyl-C-H⋯π(phen-yl) inter-actions. The overall assembly defines columns along the a-axis direction in which reside the chloro-form mol-ecules, which are stabilized by chloro-form-methine-C-H⋯S(thione) and phenyl-C-H⋯Cl contacts. The analysis of the calculated Hirshfeld surfaces, non-covalent inter-action plots and inter-action energies confirm the importance of the above-mentioned inter-actions, but also of cooperative, non-standard inter-actions such as π(benzene)⋯π(hydrogen-bond-mediated-ring) contacts.

Stacking interactions of resonance-assisted hydrogen-bridged rings and C6-aromatic rings

Stacking interactions between six-membered resonance-assisted hydrogen-bridged (RAHB) rings and C6-aromatic rings were systematically studied by analyzing crystal structures in the Cambridge Structural Database (CSD). The interaction energies were calculated by quantum-chemical methods. Although the interactions are stronger than benzene/benzene stacking interactions (-2.7 kcal mol-1), the strongest calculated RAHB/benzene stacking interaction (-3.7 kcal mol-1) is significantly weaker than the strongest calculated RAHB/RAHB stacking interaction (-4.7 kcal mol-1), but for a particular composition of RAHB rings, RAHB/benzene stacking interactions can be weaker or stronger than the corresponding RAHB/RAHB stacking interactions. They are also weaker than the strongest calculated stacking interaction between five-membered saturated hydrogen-bridged rings and benzene (-4.4 kcal mol-1) and between two five-membered saturated hydrogen-bridged rings (-4.9 kcal mol-1). SAPT energy decomposition analyses show that the strongest attractive term in RAHB/benzene stacking interactions is dispersion, however, it is mostly canceled by a repulsive exchange term; hence the geometries of the most stable structures are determined by an electrostatic term.

New heteroleptic [Ni(ii) 1,1-dithiolate-phosphine] complexes: synthesis, characterization and electrocatalytic oxygen evolution studies

Four new heteroleptic Ni(ii) complexes with general formula [Ni(ii)(LL')] (L = 2-(methylene-1,1'-dithiolato)-5-phenylcyclohexane-1,3-dione (L1) and 2-(methylene-1,1'-dithiolato)-5,5'-dimethylcyclohexane-1,3-dione (L2); L' = 1,2-bis(diphenylphosphino)ethane (dppe) and bis(diphenylphosphino)monosulphide methane (dppms) have been synthesized and characterized by elemental analysis and spectroscopy (IR, UV-Vis, 1H, 13C{1H} and 31P{1H} NMR). All complexes 1-4 have also been characterized by PXRD and single crystal X-ray crystallography. The solid state molecular structures revealed distorted square planar geometry about the four-coordinate Ni(ii) metal centre together with rare NiH-C intra/intermolecular anagostic interactions in axial positions. In these complexes supramolecular structures have been sustained by non-covalent C-HO, C-OH-O, C-Hπ, C-Hπ (NiCS2, chelate), ππ and HH interactions. Their electrocatalytic properties have been investigated for oxygen evolution reaction (OER) in which complex 2 showed the highest activity with 10 mA cm-2 at the potential of 1.58 V vs. RHE. In addition, complex 2 also exhibits an OER onset potential at 1.52 V vs. RHE.

The remarkable propensity for the formation of C–H⋯π(chelate ring) interactions in the crystals of the first-row transition metal dithiocarbamates and the supramolecular architectures they sustain

C–H⋯π(chelate ring) interactions play an important role in assembling first-row transition metal dithiocarbamates in their crystals.

Catalytic activity of new heteroleptic [Cu(PPh3)2(β-oxodithioester)] complexes: click derived triazolyl glycoconjugates

Highly efficient and reusable precatalysts of Cu(i) β-oxodithioester PPh₃ complexes for the synthesis of triazolyl glycoconjugates under “click” conditions.

Impact of substituents on the crystal structures and anti-leishmanial activity of new homoleptic Bi(iii) dithiocarbamates

Anti-leishmanial activity of six structurally characterised new functionalised homoleptic Bi(iii) dithiocarbamate complexes having monomeric, dimeric and rare polymeric structures has been explored.

Highly efficient structurally characterised novel precatalysts: di- and mononuclear heteroleptic Cu(i) dixanthate/xanthate–phosphine complexes for azide–alkyne cycloadditions

Prominent catalytic activities of novel di- and mononuclear Cu(i) xanthate/phosphine complexes have been investigated for the synthesis of triazolyl glycoconjugates using Click approach.

Investigation of interactions in Lewis pairs between phosphines and boranes by analyzing crystal structures from the Cambridge Structural Database

The interactions between phosphines and boranes in crystal structures have been investigated by analyzing data from the Cambridge Structural Database (CSD). The interactions between phosphines and boranes were classified into three types; two types depend on groups on the boron atom, whereas the third one involves frustrated Lewis pairs (FLPs). The data enabled geometric parameters in structures to be compared with phosphine-borane FLPs with classical Lewis pairs. Most of the crystal structures (78.1%) contain BH₃ as the borane group. In these systems, the boron-phosphorus distance is shorter than systems where the boron atom is surrounded by groups other than hydrogen atoms. The analysis of the CSD data has shown that FLPs have a tendency for the longest boron-phosphorus distance among all phosphine-borane pairs, as well as different other geometrical parameters. The results show that most of the frustrated phosphine-borane pairs found in crystal structures are bridged ones. The minority of non-bridged FLP structures contain, beside phosphorus and boron atoms, other heteroatoms (O, N, S for instance).

Crystal structure of the co-crystal O-isopropyl phenylcarbamothioate – 4,4′-bipyridine (2/1), C15H17N2OS

C15H17N2OS, triclinic, P1̄ (no. 2), a = 5.8595(3) Å, b = 9.2967(4) Å, c = 14.0545(8) Å, α = 83.320(4), β = 89.240(4), γ = 74.524(4), V = 732.71(7) Å3, Z = 2, R gt(F) = 0.0458, wR ref(F 2) = 0.1231, T = 100 K.

Bis(4-meth-oxy-chalcone 4-ethyl-thio-semi-carbazon-ato-κ2N1,S)zinc(II): crystal structure and Hirshfeld surface analysis

The title ZnII complex, [Zn(C19H20N3OS)2] {systematic name: bis-[(N-ethyl-N'-{(Z)-[(2E)-3-(4-meth-oxy-phen-yl)-1-phenyl-prop-2-en-1-yl-idene]amino}-carb-am-im-id-o-yl)sulfanido]zinc(II)}, features a tetra-hedrally coordinated ZnII ion within an N2S2 donor set provided by two N,S-chelating thio-semicarbazone anions. The resulting five-membered Zn,C,N2,S chelate rings adopt different conformations, i.e. almost planar and an envelope with the Zn atom being the flap atom. The configuration about the imine bond within the chelate ring is Z but those about the exocyclic imine and ethyl-ene bonds are E. In the crystal, supra-molecular [100] chains mediated by thio-amide-N-H⋯S(thione) hydrogen bonds and eight-membered thio-amide {⋯HNCS}2 synthons are observed. A range of inter-actions, including C-H⋯O, C-H⋯π, C-H⋯π(chelate ring) and π(meth-oxy-benzene)-π(chelate ring) consolidate the packing. The Hirshfeld surface analysis performed on the title complex also indicates the influence of the inter-actions involving the chelate rings upon the packing along with the more conventional contacts.

Cooperative metal–ligand influence on the formation of coordination polymers, and conducting and photophysical properties of Tl(i) β-oxodithioester complexes

Eight novel luminescent and semiconducting Tl(i) β-oxodithioester complexes forming 1D/2D coordination polymeric structures were investigated using single crystal X-ray diffraction.

Quantifying conventional C–H⋯π(aryl) and unconventional C–H⋯π(chelate) interactions in dinuclear Cu(ii) complexes: experimental observations, Hirshfeld surface and theoretical DFT study

Conventional C–H⋯π(aryl) and unconventional C–H⋯π(chelate) interactions are explored in detail.

A new monoclinic polymorph of N-(3-methyl-phen-yl)eth-oxy-carbo-thio-amide: crystal structure and Hirshfeld surface analysis

The title compound, C10H13NOS, is a second monoclinic polymorph (space group P21/c, Z' = 2) of the previously reported C2/c (Z = 1) polymorph [Tadbuppa & Tiekink (2005 ▸). Z. Kristallogr. New Cryst. Struct. 220, 395-396]. Two independent mol-ecules comprise the asymmetric unit of the new polymorph and each of these exists as a thioamide-thione tautomer. In each molecule, the central CNOS chromophore is strictly planar [r.m.s. deviations = 0.0003 and 0.0015 Å] and forms dihedral angles of 6.17 (5) and 20.78 (5)° with the N-bound 3-tolyl rings, thereby representing the major difference between the mol-ecules. The thione-S and thio-amide-N-H atoms are syn in each mol-ecule and this facilitates the formation of an eight-membered thio-amide {⋯SCNH}2 synthon between them; the dimeric aggregates are consolidated by pairwise 3-tolyl-C-H⋯S inter-actions. In the extended structure, supra-molecular layers parallel to (102) are formed via a combination of 3-tolyl-C-H⋯π(3-tol-yl) and weak π-π inter-actions [inter-centroid distance between 3-tolyl rings = 3.8535 (12) Å]. An analysis of the Hirshfeld surfaces calculated for both polymorphs reveals the near equivalence of one of the independent mol-ecules of the P21/c form to that in the C2/c form.

Mono urotropine adducts of some binary zinc xanthates and dithiocarbamates: solid-state molecular structures and supramolecular self-assembly

The molecular structures of [Zn(S2COR)2(hmta)], R=Et (I) and iPr (II), and [Zn(S2CNRR′)2(hmta)], R=R′=Et (III) and R=iPr, R′=CH2CH2OH (IV), feature chelating 1,1-dithiolate ligands and monodentate hmta molecules; hmta=hexamethylenetetramine. The resulting NS4 donor sets are highly distorted, with tendencies towards square pyramidal. Systematic differences in the structures are related to the greater chelating ability of the dithiocarbamate ligands leading to, e.g., elongated Zn–N bond lengths in III and IV. In the molecular packing, an unusual C–H···π(chelate ring) interaction is noted in III, which is correlated with the close to symmetric Zn–S bond lengths formed by the relevant dithiocarbamate ligand and resultant greater metalloaromatic character of the resulting ZnS2C chelate ring, and to the greater distortion of the coordination geometry compared with literature precedents. A three-dimensional architecture found for IV is sustained by hydroxyl-O-H···O, S and N hydrogen bonding.

Aliphatic–aromatic stacking interactions in cyclohexane–benzene are stronger than aromatic–aromatic interaction in the benzene dimer

Stacking interactions between cyclohexane and benzene were studied in crystal structures from the Cambridge Structural Database and by ab initio calculations.

Persistence of C–H⋯π(chelate ring) interactions in the crystal structures of Pd(S2COR)2. The utility of Pd(S2COR)2as precursors for palladium sulphide materials

The influence of C–H⋯π(PdS₂C) interactions in the molecular packing of Pd(S₂COR)₂increases as the steric bulk ofRincreases.

Supramolecular architectures sustained by arene-C–H…π(quasi-chelate ring) interactions in the crystal structures of copper(I) complexes

A review of the crystallographic literature is presented whereby structures featuring a quasi-six-membered chelate ring of the type {CuCl…HNCS} were evaluated for the presence of intermolecular C–H…π(quasi-chelate) interactions. These are shown to stabilise crystal structures leading to zero-, one-, two- and even three-dimensional architectures. Details of these interactions are described and a comparison to analogous interactions formed intramolecularly has been made. The C–H…π(quasi-chelate) interactions in these structures occur in one-third of structures where such contacts can potentially form.

Bipodal benzoylthiocarbamic acid esters: crystal and molecular structures of R = Et (a polymorph), and of a binuclear Cu(I) complex, R = iPr

The crystal and molecular structure of a second polymorph (P21/n) of [1,4-ROC(=S)N(H)C(=O)C6H4C(=O)N(H)C(=S)OR], R = Et, is shown to have inversion symmetry and to have a more twisted conformation than the previously reported P43212 form which has 2-fold symmetry. Despite utilising equivalent atoms in forming intermolecular interactions, very distinct crystal packing patterns are observed. Crystal characteristics and theory (DFT) are consistent with the P43212 form being more stable, a conclusion correlated with the observation that this form is the overwhelming majority of the sample (PXRD). An analysis of a binuclear copper(I) complex containing the R = iPr analogue, reveals the neutral ligand to bind via the thione-S atom resulting in a distorted ClP2S tetrahedral geometry.

Stacking interactions of hydrogen-bridged rings – stronger than the stacking of benzene molecules

Planar hydrogen-bridged rings form parallel interactions in crystal structures. The interactions can be as strong as −4.89 kcal mol⁻¹.