Richard E. Marsh (1922–2017)

Obituary for Richard Marsh.

Design, synthesis and crystallographic study of novel indole-based cyano derivatives as key building blocks for heteropolycyclic compounds of major complexity

Crystal structures have been determined for representative compounds along a four-stage synthetic sequence newly developed for the production from simple indoles of highly functionalized enolate esters as key building blocks for the synthesis of novel heteropolycyclic compounds.

A new copper(II) coordination polymer containing chains of inter­connected paddle-wheel anti­ferromagnetic clusters

In crystals of a new one-dimensional coordination polymer based on binuclear copper(II) units, two symmetry-related Cu^II centres are bridged via carboxyl­ate O atoms in a classical paddle-wheel configuration, with a Cu⋯Cu distance of 2.643 (1) Å, while bridging Cl atoms complete the square-pyramidal geometry of the metal atoms. The magnetic analysis indicates a nontrivial anti­ferromagnetic behaviour arising from alternating weak–strong anti­ferromagnetic coupling between neighbouring Cu^II centres.

Role of halogen–halogen contacts in the crystal structures of three new solvates of the drug oxyclozanide

Four solvates of oxyclozanide exhibit similar one-dimensional hydrogen-bond motifs. The lattice parameters and hydrogen-bond patterns indicate a close structural relationship between the structures in real space, but the number of short Cl⋯Cl contacts and the relative C—H⋯π distances vary and suggest that only two of the solvates are isostructural.

New pharmaceutical salts containing pyridoxine

Two new pharmaceutical salts containing pyridoxine, one member of the vitamin B6 family, and ferulic and syringic acids, respectively, were obtained and characterized by single-crystal X-ray diffraction. The inter­molecular inter­actions between the anions and cations were analyzed in detail and compared with the inter­actions found in similar pyridoxine cocrystals/salts.

Synthesis, crystal structures and properties of the new compounds K_7–xAg_1+x(XO₄)₄ (X = Mo, W)

K_7–xAg_1+x(XO₄)₄ (0 ≤ x ≤ 0.4; X = Mo, W) represent a new structure type related to the α-K₂SO₄–glaserite family. Open AgO₄ tetra­hedra have a polar disposition along the c axes. The compounds undergo first-order acentric-to-centrosymmetric polymorphous transitions.

Structural and computational analysis of inter­molecular inter­actions in a new 2-thio­uracil polymorph

A new 2-thio­uracil crystal polymorph was synthesized and characterized by single-crystal X-ray diffraction analysis. The new and a previously reported polymorph were characterized by Hirshfeld surface analysis, QTAIM computational analysis and NCI plot analysis, revealing significant differences in the inter­molecular inter­actions.

Preparation and characterization of two new Cu^II supra­molecular coordination polymers incorporating sulfobenzoate and flexible heterocyclic ligands

Two new Cu^II supra­molecular coordination polymers based on the multifunctional ligand 2-amino-4-sulfo­benzoic acid (H₂asba) have been synthesized and characterized.

Syntheses and crystal structures of two hetero­metallic iodo­plumbates containing mixed-valence copper(I/II)

By controlling the reaction conditions, Cu⁺ and Cu²⁺ can be simultaneously introduced into a Pb/I skeleton to produce two heterometallic iodo­plumbates which have been characterized by X-ray crystallography.

The march of progress: structures of the adducts of potassium dicyanidoaurate(I) with 2,2′-bi­pyridyl (redetermination) and 1,10-phenanthroline

In the 1:1 adducts of K[Au(CN)₂] with 2,2′-bipyridyl or 1,10-phenanthroline, the chelating ligands are coordinated solely to the potassium ions.

Synthesis of spiro­[indoline-3,3′-pyrrolizines] by 1,3-dipolar reactions between isatins, L-proline and electron-deficient alkenes

A one-pot reaction using simple starting materials has been used to synthesize two spiro­[indoline-3,3′-pyrrolizines] with high regio- and stereospecificity. In one compound, the supra­molecular assembly is three-dimensional, but in the other only isolated hydrogen-bonded dimers are found.

Polymorphs of the antiviral drug ganciclovir

The structure of the thermodynamically stable polymorph I of ganciclovir is reported for the first time and compared with the metastable polymorph II.

Crystallographic and computational study of a network composed of [ZnCl₄]²⁻ anions and triply protonated 4′-functionalized terpyridine cations

The structural analysis of the terpyridine-based compound (ITPH₃)₂[ZnCl₄]₃·H₂O [(ITPH₃)³⁺ is the triply protonated cation of 4′-(isoquinolin-4-yl)-2,2′:6′,2′′-terpyridine] demonstrates the concerted way in which a variety of noncovalent inter­actions, viz. hydrogen bonding, π–π and anion⋯π, participate in the crystal packing. An unexpected large enrichment ratio between the cationic C⋯N contacts can be understood in the light of their correlation with the atomic and ring NBO (natural bond order) charges.

Dimerization of a mixed-carbene Pd^II dibromide complex by elemental iodine

The reaction of a mixed carbocyclic/N-heterocyclic carbene Pd complex with an excess of iodine results in the surprising removal of a bromide ligand and the formation of a dimeric complex with penta­iodide counter-ions.

A combined crystallographic, thermal, Raman and computational study on polymorphism and phase transition in 1-(4-hex­yloxy-3-hy­droxy­phen­yl)ethanone

A triclinic phase of 1-(4-hex­yloxy-3-hy­droxy­phen­yl)ethanone is described and compared with the previously reported ortho­rhom­bic phase. The polymorphic phase transition involving the structures is analyzed.

New fluorescent compounds based on zinc thio­cyanate: influence of structure on spectral properties

New coordination compounds based on zinc thio­cyanate, namely (acetone thio­semicarbazone-κ²N¹,S)bis­(iso­thio­cyanato-κN)zinc(II) monohydrate and di­aqua­tetra­kis­(urea-κO)zinc(II) tetra­kis­(iso­thio­cyanato-κN)zinc(II), produce fluorescence (blue and green, respectively) upon irradiation with violet light. The spectral properties were correlated with the observed mol­ecular and supra­molecular structures.

Conformational study of (Z)-5-(4-chloro­benzyl­idene)-2-[4-(2-hy­droxy­eth­yl)piperazin-1-yl]-3H-imidazol-4(5H)-one in different environments: insight into the structural properties of bacterial efflux pump inhibitors

In order to study the influence of the environment on the conformation of (Z)-5-(4-chloro­benzyl­idene)-2-[4-(2-hy­droxy­eth­yl)piperazin-1-yl]-3H-imidazol-4(5H)-one, the salts with picolinic and 4-nitro­phenyl­acetic acids were prepared. In both crystal structures, the imidazolone mol­ecule is protonated at an N atom of the piperazine ring by proton transfer from the corresponding acid. The carboxyl­ate groups are engaged in hydrogen bonds with the cations, resulting in different orientations of the hy­droxy­ethyl group.

The Nature of the Mechanical Bond: From Molecules to Machines