Structural peculiarities and anticancer activities of two organotin compounds

When solvent becomes reactant: a study of 6-aminothiocytosine derivatives

The dissolution of 6-aminothiocytosine in common solvents (such as methanol, dimethyl sulfoxide and dichloromethane) under alkaline conditions is shown to afford new compounds with a 6-aminothiocytosine skeleton: 2,2′-disulfanediylbis(pyrimidine-4,6-diamine) (1), C8H10N8S2, 2,2′-[methanediylbis(sulfanediyl)]bis(pyrimidine-4,6-diamine) (2), C9H12N8S2, 2-[(methoxymethyl)sulfanyl]pyrimidine-4,6-diamine (3), C6H10N4OS, and poly[(μ-4,6-diaminopyrimidine-2-sulfinato)potassium(I)] (4), [K(C4H5N4O2S)] n . The crystal architectures of these compounds are found to be strongly influenced by extensive hydrogen-bond networks, although some individual features are also observed. Specifically, 1 is characterized by very short C—H...N hydrogen bonds, 2 features apparently weak and long C—H...π, C—H...S and π–π contacts as the greatest contributors to stabilization energy, while 3 contains ribbons of molecules formed by centrosymmetric dimers of two types, and 4 is characterized by layers with principal structural units comprising distorted six-molecule rings. The intermolecular interactions in 1–4 are characterized in terms of their geometry, topology and energy, and the corresponding results are confirmed and visualized using Hirshfeld surface analysis.

Solvent influence on the crystal packing of 6-aminothiocytosine

The crystal structures of 6-aminothiocytosine (systematic name: 4,6-diamino-1,2-dihydropyrimidine-2-thione, DAPMT, C₄H₆N₄S), its hemihydrate (0.5H₂O) and its dimethylformamide (DMF, C₃H₇NO) monosolvate were compared, and the influence of the type of solvent on the supramolecular motifs was analysed. In all three crystal structures, there are two symmetry-independent molecules (A and B), and these molecules are connected by three relatively short and directional hydrogen bonds to form chains of alternating A and B molecules. A further organization of these chains is dependent on the nature of the solvent molecule. In the unsolvated form, two orientations of the neighbouring chains are observed, and similar motifs - but only one per structure - can be observed in the solvated structures. These two different motifs can be connected by two different kinds of contacts, i.e. either π-π (hemihydrate) or staple-supported S...S (DMF). In the crystal structures, the O atoms of the solvent molecules are double acceptors of the same type of hydrogen bonds and bind the chains of DAPMT molecules into different motifs (dimeric or infinite chains). A Hirshfeld fingerprint analysis was used for visualization and additional interpretation of these results.

Structural and Thermal Studies of New Triphenyltin Complexes

Crystal and molecular structures of new triorganotin complexes have been determined via X-ray diffraction. These complexes include, among others, the second polymorph of Ph₃Sn(thiocytosine), the double complex salt Ph₃Sn(methimazole)₂·Ph₃SnCl₂, and five-coordinated triphenyltin chloride with methimazole, tetrahydopyrimidine-2-thione, dimethylformamide, and dimethyl sulfoxide. Hirshfeld surface analysis allowed for better visualization and precise pinpointing of the differences between polymorphs as well as easier analysis of intermolecular interactions. All of the new structure of the Ph₃Sn(L)Cl type displayed interesting thermal features and therefore were also analyzed via thermogravimetric analysis/simultaneous thermal analysis/differential scanning calorimetry methods. These analyses showed the different ways in which these complexes underwent thermal decomposition. In some cases, to solve the problems that arose, powder X-ray diffraction analyses have also been performed.

Investigating the structural chemistry of organotin(IV) compounds: recent advances

Organotin(IV) compounds have been considered for their outstanding industrial, medical and specific applications in the synthesis of various types of chemical compounds. In this review, we have focused on the structural chemistry of organotin(IV) compounds, including coordination chemistry, the effect of structure on reactions, bond formations from the perspective of structure and investigation of the structure of organotin(IV) compounds in different phases. The structural chemistry of organotin(IV) compounds is subject to interest due to their major impact on predicting the properties and drumming up support for pushing back the frontiers of synthesis of organotin(IV) compounds with advanced properties.