Discrete supramolecular architecture vs crystal engineering: the rational design of a platinum-based bimetallic assembly with a chairlike structure and its infinite, copper analogue

Ionic cocrystals of dithiobispyridines: the role of I...I halogen bonds in the building of iodine frameworks and the stabilization of crystal structures

It has been confirmed that mercaptopyridines undergo spontaneous condensation in redox reaction with iodine-forming dithiopyridines. In the solid state, these compounds are protonated at the N atoms and cocrystallize with iodine forming salt structures, namely, 2-[(pyridin-2-yl)disulfanyl]pyridinium triiodide sesquiiodine, C₁₀H₉N₂S₂⁺·I₃^-·1.5I₂, and 4,4'-(disulfanediyl)dipyridinium pentaiodide triiodide, C₁₀H₁₀N₂S₂²⁺·I₅^-·I₃^-. Dithiopyridine cations are packed among three-dimensional frameworks built from iodide anions and neutral iodine molecules, and are linked by hydrogen, halogen and chalcogen interactions. Quantum chemical computations indicated that dithiopyridines exhibit anomalously high nitrogen basicity which qualify them as potential proton sponges.

Anion-Recognition Studies of a Rhenium(I) 4-Mercaptopyridine Compound and Its Ligand-Coupling Products

The reaction of Re(CO)₅Cl with 4-mercaptopyridine (4-PySH) led to the formation of [Re(CO)₃(4-HPyS)₃]Cl (1), showing three hydrogen-bonding donors of 4-PySH ligands as well as a characteristic ligand-to-metal charge-transfer absorption at ca. 380 nm. In this regard, a variety of anions, i.e., CN^-, OAc^-, F^-, Cl^-, Br^-, I^-, PF₆^-, NO₃^-, ClO₄^-, and H₂PO₄^-, were examined to study anion-recognition studies through hydrogen-bonding functionalities. Upon the addition of CN^- to a methanolic solution of complex 1, a remarkable spectral change with an isosbestic point at ca. 314 nm in the absorption spectra was observed, with a binding constant (K_b) calculated to be 24770 M^-1. Moreover, the OAc^- anion also shows a similar trend, but a mild spectral change, with K_b calculated to be 2170 M^-1. Unlike those of CN^- and OAc^-, the addition of F^-, Cl^-, Br^-, and I^- anions causes a less pronounced spectral change with an isosbestic point at ca. 350 nm and K_b calculated to be 2863-750 M^-1. However, almost no spectral change can be observed for other anions (i.e., PF₆^-, NO₃^-, H₂PO₄^-, and ClO₄^-). Interestingly, the molecular loops of [Re(CO)₃Cl(Py₂S₂)]₂ (2; Py₂S₂ = 4,4'-dipyridyl disulfide) and [Re(CO)₃Cl(Py₂S)_0.35(Py₂S₂)_0.65]₂ (3; Py₂S = 4,4'-dipyridyl sulfide) can be isolated and structurally characterized by X-ray diffraction, where those crystals were grown from diethyl ether diffusion into a methanolic solution of complex 1 with [Bu₄N]CN and [Bu₄N]NO₃, respectively. It is noted that such unusual ligand-coupling reactions toward the homoligand and hybrid-ligand loops of complexes 2 and 3 can be achieved at room temperature in this study.

Application of 4-pyridylselenolate palladium macrocycles in Suzuki couplings

Pd macrocycles of diphosphine were constructed employing 4-pyridylselenolate. They act as excellent catalysts in the Suzuki coupling reaction.

Halogen Bonds Fabricate 2D Molecular Self-Assembled Nanostructures by Scanning Tunneling Microscopy

Halogen bonds are currently new noncovalent interactions due to their moderate strength and high directionality, which are widely investigated in crystal engineering. The study about supramolecular two-dimensional architectures on solid surfaces fabricated by halogen bonding has been performed recently. Scanning tunneling microscopy (STM) has the advantages of realizing in situ, real-time, and atomic-level characterization. Our group has carried out molecular self-assembly induced by halogen bonds at the liquid–solid interface for about ten years. In this review, we mainly describe the concept and history of halogen bonding and the progress in the self-assembly of halogen-based organic molecules at the liquid/graphite interface in our laboratory. Our focus is mainly on (1) the effect of position, number, and type of halogen substituent on the formation of nanostructures; (2) the competition and cooperation of the halogen bond and the hydrogen bond; (3) solution concentration and solvent effects on the molecular assembly; and (4) a deep understanding of the self-assembled mechanism by density functional theory (DFT) calculations.

Synthesis and anti-proliferative activities of amine capped Pd and Pt macrocycles of 4,4′-dipyridylselenides

Symmetric macrocyclic complexes characterized as dimeric and their oligomeric form in water and the solid state exhibit high in vitro anticancer activities.

Xantphos-Capped Pd(II) and Pt(II) Macrocycles of Aryldithiolates: Structural Variation and Catalysis in C-C Coupling Reaction

The self-assembly of Xantphos-capped M(OTf)₂ (M = cis-[M'(Xantphos)]²⁺; M' = Pd, Pt) with bridging ligands 1,4-benezenedithiol or 4,4'-biphenyldithiol has been investigated. The reactions have yielded complexes [M{S(C₆H₄) _nSH}]₂(OTf)₂ (I) and [M₂{S(C₆H₄) _nS}]₂(OTf)₄ (II) ( n = 1 or 2). The equilibrium between I and II has been established in platinum complexes for n = 2, whereas the analogous Pd complex exclusively exist as II. These results are different from our previously reported dppe or triethyl phosphine-capped complexes which showed only type II. The same reaction with 1,3-benezenedithiol lead to the complex [M₂(SC₆H₄SSC₆H₄S)](OTf)₂ (III), containing a S-S bond between two thiolate ligands, formed via a complex of type I in solution. Characterization of the complexes was accomplished by NMR spectroscopy, UV-vis spectroscopy and mass spectrometry, and X-ray crystallography. Density functional calculations were performed to estimate the relative stability of three types of complexes. The palladium complexes are excellent catalysts in Suzuki C-C cross coupling reactions under mild conditions, and can be reused eight times without losing significant yield. The activity of the Pd catalysts derived from three dithiol ligand follows opposite trend of the stability as III > II > I. The comparative catalytic activity of the tetranuclear Pd complexes (II) of bis-phosphines of varied bite angles, including the structurally characterized [Pd₂(dppf)₂(SC₁₂H₈S)]₂(OTf)₄ has also been demonstrated.

A simultaneous disulfide bond cleavage, N,S-bialkylation/N-protonation and self-assembly reaction: syntheses, structures and properties of two hybrid iodoargentates with thiazolyl-based heterocycles

Unprecedented multiple in situ reactions were found during preparation of hybrid iodoargentates.

Solvent-controlled three families of Zn(ii) coordination compounds: synthesis, crystal structure, solvent-induced structural transformation, supramolecular isomerism and photoluminescence

The assembly, topological structure, supramolecular isomerism and luminescence of three solvent-controlled families of Zn(ii) coordination compounds were reported here.

Porous ZnO/Co3O4 heteronanostructures derived from nano coordination polymers for enhanced gas sorption and visible light photocatalytic applications

Porous ZnO/Co₃O₄ heteronanostructures are successfully fabricated by a one-step solid state conversion of a novel [(Zn)_x–(Co)_7−x(BDC)(DHS)]·nH₂O (x = 1, 3, 4, 6)] nano coordination polymers (NCPs).

A series of nano/micro-sized metal–organic frameworks with tunable photoluminescence properties

Hierarchically assembled nanostructures of lanthanide-based MOFs with tunable emission have been successfully fabricated via a simple method at room temperature.

Self-triggered conformations of disulfide ensembles in coordination polymers with multiple metal clusters

Five coordination polymers containing manganese(ii) ions, 6,6′-dithiodinicotinate, and/or N-donor coligands display mononuclear, trinuclear cluster and polymeric metal oxide wire and exhibit intrinsic biomimetic characteristics.