Crystal structure and Hirshfeld surface analysis of bis(6,7,8,9-tetrahydro-11H-pyrido[2,1-b]quinazolin-5-ium) tetrachloridozincate

The title compound, (C12H15N2)2[ZnCl4], is a salt with two symmetrically independent, essentially planar heterocyclic cations and a slightly distorted tetrahedral chlorozincate dianion. N—H...Cl hydrogen bonds link these ionic constituents into a discrete aggregate, which comprises one formula unit. The effect of hydrogen bonding is reflected in the minor distortions of the [ZnCl4]2− moiety: distances between the cation and chlorido ligands engaged in classical hydrogen bonds are significantly longer than the others. Secondary interactions comprise C—H...π hydrogen bonding and weak π–π stacking. A Hirshfeld surface analysis indicates that the most abundant contacts in packing stem from H...H (47.8%) and Cl...H/H...Cl (29.3%) interactions.

Formation of uranyl phthalate coordination polymers with unusual 2D net topologies in the presence of organic cations

Inclusion of heterocyclic cations into a uranyl-phthalate system allowed the formation of 2D coordination polymers whose topological analysis revealed that the underlying nets had unusual topologies.

A New Generation of Minor-Groove-Binding—Heterocyclic Diamidines That Recognize G·C Base Pairs in an AT Sequence Context

We review the preparation of new compounds with good solution and cell uptake properties that can selectively recognize mixed A·T and G·C bp sequences of DNA. Our underlying aim is to show that these new compounds provide important new biotechnology reagents as well as a new class of therapeutic candidates with better properties and development potential than other currently available agents. In this review, entirely different ways to recognize mixed sequences of DNA by modifying AT selective heterocyclic cations are described. To selectively recognize a G·C base pair an H-bond acceptor must be incorporated with AT recognizing groups as with netropsin. We have used pyridine, azabenzimidazole and thiophene-N-methylbenzimidazole GC recognition units in modules crafted with both rational design and empirical optimization. These modules can selectively and strongly recognize a single G·C base pair in an AT sequence context. In some cases, a relatively simple change in substituents can convert a heterocyclic module from AT to GC recognition selectivity. Synthesis and DNA interaction results for initial example lead modules are described for single G·C base pair recognition compounds. The review concludes with a description of the initial efforts to prepare larger compounds to recognize sequences of DNA with more than one G·C base pairs. The challenges and initial successes are described along with future directions.

Polymeric iodobismuthates {[Bi3I10]} and {[BiI4]} with N-heterocyclic cations: promising perovskite-like photoactive materials for electronic devices

Structurally different complex bismuth iodides with 1D anionic frameworks were designed and explored as semiconductor materials for photovoltaic devices.