Unusual {···HNC2O···HCnO}, n = 1 or 2, synthons predominate in the molecular packing of the one-dimensional coordination polymers, {Cd[S2P(OR)2]2(3LH2)}n, for R = Me and Et, but are precluded when R = i-Pr; 3LH2 = N,N′-bis(3-pyridylmethyl)oxalamide

Linear, one-dimensional coordination polymers, {Cd[S2P(OR)2]2(3LH2)}n, for R = Me (1), Et (2) and i-Pr (3) have been fully characterised by a variety of physiochemical, spectroscopic, crystallographic and computational techniques. Two-dimensional...

A Structural Survey of Poly-Functional Dithiocarbamate Ligands and the Aggregation Patterns They Sustain

An overview is presented of the crystal structures of transition metal, main group element, and lanthanide compounds containing poly-functional dithiocarbamate ligands, namely species containing two or more connected NCS2− residues. In all, there are 40 different ligands of this type that have been characterised crystallographically in their heavy-element compounds with up to six NCS2− residues; all are bridging. In most cases, the resulting aggregates are zero-dimensional, often di-nuclear, but aggregates of up to 36 metal (gold) atoms are noted. There are smaller numbers of one-, two-, and three-dimensional architectures sustained by poly-functional dithiocarbamate ligands in their respective crystals. The survey highlights the opportunities afforded by this generally under-studied class of ligand.

Exploring the Topological Landscape Exhibited by Binary Zinc-triad 1,1-dithiolates

The crystal chemistry of the zinc-triad binary 1,1-dithiolates, that is, compounds of xanthate [−S2COR], dithiophosphate [−S2P(OR)2], and dithiocarbamate [−S2CNR2] ligands, is reviewed. Owing to a wide range of coordination modes that can be adopted by 1,1-dithiolate anions, such as monodentate, chelating, μ2-bridging, μ3-bridging, etc., there exists a rich diversity in supramolecular assemblies for these compounds, including examples of zero-, one-, and two-dimensional architectures. While there are similarities in structural motifs across the series of 1,1-dithiolate ligands, specific architectures are sometimes found, depending on the metal centre and/or on the 1,1-dithiolate ligand. Further, an influence of steric bulk upon supramolecular aggregation is apparent. Thus, bulky R groups generally preclude the close approach of molecules in order to reduce steric hindrance and therefore, lead to lower dimensional aggregation patterns. The ligating ability of the 1,1-dithiolate ligands also proves crucial in determining the extent of supramolecular aggregation, in particular for dithiocarbamate species where the relatively greater chelating ability of this ligand reduces the Lewis acidity of the zinc-triad element, which thereby reduces its ability to significantly expand its coordination number. Often, the functionalisation of the organic substituents in the 1,1-dithiolate ligands, for example, by incorporating pyridyl groups, can lead to different supramolecular association patterns. Herein, the diverse assemblies of supramolecular architectures are classified and compared. In all, 27 structurally distinct motifs have been identified.

Crystal structures and Hirshfeld surface analyses of (N-hexyl-N-methyl-dithio-carbamato-κ2S,S')triphenyl-tin(IV) and [N-methyl-N-(2-phenyl-ethyl)-dithio-carbamato-κ2S,S']tri-phenyl-tin(IV)

The crystal and mol-ecular structures of two tri-phenyl-tin di-thio-carbamate compounds, viz. [Sn(C6H5)3(C8H16NS2)], (I), and [Sn(C6H5)3(C10H12NS2)], (II), are described. The di-thio-carbamate ligand in each mol-ecule coordinates in an asymmetric fashion resulting in heavily distorted tetra-hedral C3S coordin-ation geometries for the Sn atoms, with the distortions traced to the close approach of the non-coordinating thione-S atom. The mol-ecular packing in both compounds features C-H⋯π(Sn-phen-yl) inter-actions. In (I), the donors are Sn-phenyl-C-H groups leading to centrosymmetric aggregates, while in (II), the donors are both Sn-phenyl-C-H and methyl-C-H groups leading to supra-molecular chains propagating along the b axis. The identified aggregates assemble into their respective crystals with no directional inter-actions between them. An analysis of the Hirshfeld surfaces show distinctive patterns, but an overwhelming predominance (>99% in each case) of H⋯H, C⋯H/H⋯C and S⋯H/H⋯S contacts on the respective Hirshfeld surface.

A two-dimensional coordination polymer: poly[[bis-[μ2-N-ethyl-N-(pyridin-4-ylmeth-yl)di-thio-carbamato-κ3N:S,S']cadmium(II)] 3-methyl-pyridine monosolvate]

The title compound, {[Cd(C9H11N2S2)2]·C6H7N} n , features two μ2-κ3-di-thio-carbamate ligands each of which chelates one CdII atom, via the S atoms, while simultaneously bridging to another via the pyridyl-N atom. The result is a two-dimensional coordination polymer extending parallel to the ab plane with square channels along the b axis. The CdII atom geometry is based on a distorted cis-N2S4 octa-hedron. The 3-methyl-pyridine mol-ecules reside in the channels aligned along the b axis, being held in place by methyl-ene-C-H⋯N(3-methyl-pyridine) and (3-methyl-pyridine)-C-H⋯π(pyrid-yl) inter-actions. Pyridyl-C-H⋯S and di-thio-carbamate-methyl-C-H⋯π(pyrid-yl) inter-actions provide connections between layers along the c axis.

[N'-(4-Dec-yloxy-2-oxido-benzyl-idene)-3-hy-droxy-2-naphtho-hydrazidato-κ3N,O,O']di-methyl-tin(IV): crystal structure and Hirshfeld surface analysis

The title diorganotin compound, [Sn(CH3)2(C28H32N2O4)], features a distorted SnC2NO2 coordination geometry almost inter-mediate between ideal trigonal-bipyramidal and square-pyramidal. The dianionic Schiff base ligand coordinates in a tridentate fashion via two alkoxide O and hydrazinyl N atoms; an intra-molecular hy-droxy-O-H⋯N(hydrazin-yl) hydrogen bond is noted. The alk-oxy chain has an all-trans conformation, and to the first approximation, the mol-ecule has local mirror symmetry relating the two Sn-bound methyl groups. Supra-molecular layers sustained by imine-C-H⋯O(hy-droxy), π-π [between dec-yloxy-substituted benzene rings with an inter-centroid separation of 3.7724 (13) Å], C-H⋯π(arene) and C-H⋯π(chelate ring) inter-actions are formed in the crystal; layers stack along the c axis with no directional inter-actions between them. The presence of C-H⋯π(chelate ring) inter-actions in the crystal is clearly evident from an analysis of the calculated Hirshfeld surface.

fac-Aceto-nitrile-tricarbon-yl(di-methyl-carbamodi-thio-ato-κ2S,S')rhenium(I): crystal structure and Hirshfeld surface analysis

The title compound, [Re(C3H6NS2)(C2H3N)(CO)3], features an octa-hedrally coordinated ReI atom within a C3NS2 donor set defined by three carbonyl ligands in a facial arrangement, an aceto-nitrile N atom and two S atoms derived from a symmetrically coordinating di-thio-carbamate ligand. In the crystal, di-thio-carbamate-methyl-H⋯O(carbon-yl) inter-actions lead to supra-molecular chains along [36-1]; both di-thio-carbamate S atoms participate in intra-molecular methyl-H⋯S inter-actions. Further but weaker aceto-nitrile-C-H⋯O(carbonyl) inter-actions assemble mol-ecules in the ab plane. The nature of the supra-molecular assembly was also probed by a Hirshfeld surface analysis. Despite their weak nature, the C-H⋯O contacts are predominant on the Hirshfeld surface and, indeed, on those of related [Re(CO)3(C3H6NS2)L] structures.

Supramolecular association in (μ2-pyrazine)-tetrakis(N,N-bis(2-hydroxyethyl)dithiocarbamato)dizinc(II) and its di-dioxane solvate

The crystal and molecular structures of {Zn[S2CN(CH2CH2OH)2]2}2(pyrazine), (1), and its di-dioxane solvate, (2), are described. In each of these, the centrosymmetric, binuclear molecule features a five-coordinated, highly distorted square-pyramidal geometry based on a NS4 donor set. The three-dimensional architectures in 1 and 2 are sustained by extensive networks of distinctive hydroxyl-O–H···O(hydroxyl) hydrogen bonding. The topology of the lattices are very different with that of 2 having a more regular appearance. The dioxane molecules reside in channels defined by the host molecules in 2 but, do not make many significant interactions with the host. The fact that 1 exhibits a significantly greater packing efficiency and a higher density suggests 1 is more stable than 2. The retention of dioxane in crystals of 2 probably reflects its intimate involvement in nucleation and high boiling point, meaning it is retained during crystallisation. Hirshfeld surface analyses were conducted and confirm the importance of the hydroxyl-O–H···O(hydroxyl) hydrogen bonding but, also reveal the presence of other interactions, most notably C–H···π(chelate) interactions.

Bis(N,N-di-ethyl-dithio-carbamato-κ2S,S')(3-hy-droxy-pyridine-κN)zinc and bis-[N-(2-hy-droxy-eth-yl)-N-methyldithio-carbamato-κ2S,S'](3-hy-droxy-pyridine-κN)zinc: crystal structures and Hirshfeld surface analysis

The common feature of the mol-ecular structures of the title compounds, [Zn(C5H10NS2)2(C5H5NO)], (I), and [Zn(C4H8NOS2)2(C5H5NO)], (II), are NS4 donor sets derived from N-bound hy-droxy-pyridyl ligands and asymmetrically chelating di-thio-carbamate ligands. The resulting coordination geometries are highly distorted, being inter-mediate between square pyramidal and trigonal bipyramidal for both independent mol-ecules comprising the asymmetric unit of (I), and significantly closer towards square pyramidal in (II). The key feature of the mol-ecular packing in (I) is the formation of centrosymmetric, dimeric aggregates sustained by pairs of hy-droxy-O-H⋯S(di-thio-carbamate) hydrogen bonds. The aggregates are connected into a three-dimensional architecture by methyl-ene-C-H⋯O(hy-droxy) and methyl-C-H⋯π(chelate) inter-actions. With greater hydrogen-bonding potential, supra-molecular chains along the c axis are formed in the crystal of (II), sustained by hy-droxy-O-H⋯O(hy-droxy) hydrogen bonds, with ethyl-hydroxy and pyridyl-hydroxy groups as the donors, along with ethyl-hydroxy-O-H⋯S(di-thio-carbamate) hydrogen bonds. Chains are connected into layers in the ac plane by methyl-ene-C-H⋯π(chelate) inter-actions and these stack along the b axis, with no directional inter-actions between them. An analysis of the Hirshfeld surfaces clearly distinguished the independent mol-ecules of (I) and reveals the importance of the C-H⋯π(chelate) inter-actions in the packing of both (I) and (II).

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.

An unprecedented binuclear cadmium di-thio-carbamate adduct: bis-[μ2-N-(2-hydroxy-eth-yl)-N-iso-propyl-carbamodi-thio-ato-κ3S:S,S']bis-{[N-(2-hydroxy-eth-yl)-N-iso-propyl-carbamodi-thio-ato-κ2S,S'](3-{(1E)-[(E)-2-(pyridin-3-yl-methyl-idene)hydrazin-1-yl-idene]meth-yl}pyridine-κN)cadmium]} dihydrate

The asymmetric unit in the title binuclear compound, [Cd(C6H12NOS2)2(C12H10N4)]2·2H2O, comprises a CdII atom, two di-thio-carbamate (dtc) anions, a monodentate 3-pyridine-aldazine ligand and a lattice water mol-ecule. The binuclear mol-ecule is constructed by the application of inversion symmetry. One dtc ligand simultaneously chelates one cadmium atom and bridges the centrosymmetric mate, while the other dtc ligand is chelating only. This leads to a centrosymmetric [Cd(dtc)2]2 core to which are appended two 3-pyridine-aldazine ligands. The resulting NS5 donor set is based on an octa-hedron. The three-dimensional mol-ecular packing is sustained by hydroxyl-O-H(hydrox-yl) and water-O-H⋯O(hydrox-yl) hydrogen bonding, leading to supra-molecular layers parallel to (101) which are connected by water-O-H⋯N(pyrid-yl) hydrogen bonding; additional C-H⋯O, S π(chelate ring) inter-actions are also evident. The retention of the central [Cd(dtc)2]2 core upon adduct formation is unprecedented in the structural chemistry of the zinc-triad di-thio-carbamates.

[μ2-trans-1,2-Bis-(pyridin-4-yl)ethene-κ(2) N:N']bis-{[1,2-bis-(pyridin-4-yl)ethene-κN]bis-[N-(2-hydroxy-eth-yl)-N-iso-propyl-dithio-carbamato-κ(2) S,S']cadmium} aceto-nitrile tetra-solvate: crystal structure and Hirshfeld surface analysis

The asymmetric unit of the title compound, [Cd2(C12H10N2)3(C6H12NOS2)4]·4C2H3N, comprises a Cd(II) atom, two di-thio-carbamate (dtc) anions, one and a half trans-1,2-dipyridin-4-yl-ethyl-ene (bpe) mol-ecules and two aceto-nitrile solvent mol-ecules. The full binuclear complex is generated by the application of a centre of inversion. The dtc ligands are chelating, one bpe mol-ecule coordinates in a monodentate mode while the other is bidentate bridging. The resulting cis-N2S4 coordination geometry is based on an octa-hedron. Supra-molecular layers, sustained by hy-droxy-O-H⋯O(hy-droxy) and hy-droxy-O-H⋯N(bpe) hydrogen bonding, inter-penetrate to form a three-dimensional architecture; voids in this arrangement are occupied by the aceto-nitrile solvent mol-ecules. Additional inter-molecular inter-actions falling within the specified framework have been analysed by Hirshfeld surface analysis, including π-π inter-actions.