Dinuclear Macrocyclic Palladium Dithiocarbamates Derived from the Homologous Series of Aliphatic 1,x-Diamines (x= 4-10)

A Catalogue of Orthogonal Complementary Ligand Pairings for Palladium(II) Complexes

Molecular recognition is a form of information transfer, seen in the base pairing in DNA which is derived from the identity (acceptor or donor) and number of hydrogen bond sites within each base. Here we report bis-ligand palladium(II) complexes that exhibit similar complementarity. Pd(II) has square planar four-coordinate geometry, giving control over ligand orientation and denticity. Pairings were developed using ligand denticity (3 : 1 or 2 : 2), and hydrogen bond capability (AA:DD or AD:DA) or lack thereof. Five pairings were investigated, with two sets of four being found fully orthogonal. The two 3 : 1 pairings exhibited limited ligand exchange. The extent of this exchange varied dependant on solvent from 2 : 1 (desired to undesired) to 6 : 1. A reliable and varied set of ligand pairs have therefore been developed for bis-ligand coordination sphere engineering in pursuit of sorting for complex molecular architectures and molecular-level information storage and transfer events.

Dithiocarbamate Complexes of Platinum Group Metals: Structural Aspects and Applications

The incorporation of dithiocarbamate ligands in the preparation of metal complexes is largely prompted by the versatility of this molecule. Fascinating coordination chemistry can be obtained from the study of such metal complexes ranging from their preparation, the solid-state properties, solution behavior as well as their applications as bioactive materials and luminescent compounds, to name a few. In this overview, the dithiocarbamate complexes of platinum-group elements form the focus of the discussion. The structural aspects of these complexes will be discussed based upon the intriguing findings obtained from their solid- (crystallographic) and solution-state (NMR) studies. At the end of this review, the applications of platinum-group metal complexes will be discussed.

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.

Electron belt-to-σ-hole switch of noncovalently bound iodine(i) atoms in dithiocarbamate metal complexes

The nature of metals in the isostructural series of dithiocarbamate complexes affects the electron belt-to-σ-hole switch of noncovalently bound iodine(i) leading to either semicoordination, or halogen bonding.

Flexible Viologen Cyclophanes: Odd/Even Effects on Intramolecular Interactions

The ability of three bis-viologen cyclophanes to act as redox-triggered contractile switches is investigated. Odd/even effects in the formation of cyclic bis-viologens are circumvented by the use of a Zincke salt intermediate and a tetrathiafulvalene template to prepare a flexible cyclophane with hexyl linkers. Comparative spectro-electrochemical studies of this macrocycle with two other pentyl- or heptyl-linked cyclic bis-viologens show that the development of intramolecular interactions in aqueous solution depends on the length of the bridges. This dependence is confirmed by EPR and DFT studies of the magnetic coupling in the diradical dication species. The anti-ferromagnetic or ferromagnetic nature of the coupling depend, respectively, on the odd or even number of methylene groups in the spacer.

Variation of the Molecular Conformation, Shape, and Cavity Size in Dinuclear Metalla-Macrocycles Containing Hetero-Ditopic Dithiocarbamate-Carboxylate Ligands from a Homologous Series of N-Substituted Amino Acids

A homologous series of dithiocarbamate ligands derived from N-substituted amino acids was reacted with different diorganotin dichlorides to give 18 diorganotin complexes. Spectroscopic and mass spectrometric analysis evidenced the formation of assemblies with six-coordinate tin atoms embedded in skewed-trapezoidal bipyramidal coordination environments of composition C₂SnS₂O₂. Single-crystal X-ray diffraction analysis for three of the compounds revealed a one-dimensional polymeric structure for the complex with the ligand derived from 5-aminopentanoic acid, which through further intermolecular Sn···O interactions generated an overall two-dimensional coordination polymer containing 40-membered hexanuclear tin macrocycles. On the contrary, the ligands derived from 6-aminohexanoic and 8-aminooctanoic acid provided the expected 22- and 26-membered dinuclear macrocyclic structures. Density functional theory calculations for a representative series of macrocyclic complexes of composition [Me₂SnLx]₂ with Lx = ¯S₂CN(Me)-(CH₂)_x-COO¯ (x = 3-12) enabled a detailed analysis of the variations in the molecular conformation, shape, and cavity size of the macrocycles in dependence of the aliphatic spacer. Because of odd-even effects, the difunctional ligands can adopt either a curved or a twisted-pincer shape, while the SnS_xO_4-x (x = 0-4) moieties can act either as linear or angular tectons with varying connectivity angles.

A, Singh VK. Synthesis and spectral characterization of bimetallic metallomacrocyclic structures [MII2-μ2-bis-{(κ2S,S-S2CN(R)C6H4)2O}] (M = Ni/Zn/Cd): density functional theory and host–guest reactivity studies

Compounds displayed the ability to form 1 : 1 host–guest inclusion complexes with bidentate guests and to form metal sulphides on thermal degradation.

Self-assembly of a fac-Mn(CO)3-core containing dinuclear metallacycles using flexible ditopic linkers

Flexible dimanganese metallacycles have been achieved using Mn(CO)₅Br and adaptable ditopic pyridyl linkers. The host–guest chemistry of Mn(i)-dinuclear metallacycles has been explored.

Vysotskite structured photoactive palladium sulphide thin films from dithiocarbamate derivatives

Palladium dithiocarbamate precursors have been designed for the fabrication of palladium sulphide photoelectrode films using aerosol assisted chemical vapour deposition.