Study of the Counter Cation Effects on the Supramolecular Structure and Electronic Properties of a Dianionic Oxamate-Based {Ni} Helicate.

Herein, we describe the synthesis, crystal structure, and electronic properties of {[K(dmso)(HO)][Ni(Hmpba)]·dmso·2HO} () and [Ni(HO)][Ni(Hmpba)]·3CHOH·4HO () [dmso = dimethyl sulfoxide; CHOH = methanol; and Hmpba = 1,3-phenylenebis(oxamic acid)] bearing the [Ni(Hmpba)] helicate, hereafter referred to as {Ni}. SHAPE software calculations indicate that the coordination geometry of all the Ni atoms in 1 and 2 is a distorted octahedron (O) whereas the coordination environments for K1 and K2 atoms in 1 are Snub disphenoid J84 (D) and distorted octahedron (O), respectively. The {Ni} helicate in is connected by K counter cations yielding a 2D coordination network with topology.

Building-up host-guest helicate motifs and chains: a magneto-structural study of new field-induced cobalt-based single-ion magnets.

In this work, we present the synthetic pathway, a refined structural description, complete solid-state characterization and the magnetic properties of four new cobalt(ii) compounds of formulas [Co(HO)][Co(Hmpba)]·2HO·0.5dmso (1), [Co(HO)][Co(Hmpba)]·3HO·0.5dpss (2), [Co(Hmpba)(HO)]·4nHO (3), and [Co(Hmpba)(CHOH)(HO)]·0.

ss-NMR and single-crystal X-ray diffraction in the elucidation of a new polymorph of bischalcone (1E,4E)-1,5-bis(4-fluorophenyl)penta-1,4-dien-3-one.

We report a new polymorph of (1E,4E)-1,5-bis(4-fluorophenyl)penta-1,4-dien-3-one, CHFO. Contrary to the precedent literature polymorph with Z' = 3, our polymorph has one half molecule in the asymmetric unit disordered over two 50% occupancy sites. Each site corresponds to one conformation around the single bond vicinal to the carbonyl group (so-called anti or syn).

Exploring the structural landscape of 2-(thiophen-2-yl)-1,3-benzothiazole: high-Z' packing polymorphism and cocrystallization with calix[4]tube.

We report here for the first time a cocrystal of the so-called neutral calix[4]tube, which is two tail-to-tail-arranged and partially deprotonated tetrakis(carboxymethoxy)calix[4]arenes, including three sodium ions, with 2-(thiophen-2-yl)-1,3-benzothiazole, namely trisodium bis(carboxymethoxy)bis(carboxylatomethoxy)calix[4]arene tris(carboxymethoxy)(carboxylatomethoxy)calix[4]arene-2-(thiophen-2-yl)-1,3-benzothiazole-dimethyl sulfoxide-water (1/1/2/2), 3Na·CHO·CHO·CHNS·2CHOS·2HO, which provides a new approach into the host-guest chemistry of inclusion complexes. Three packing polymorphs of the same benzothiazole with high Z' (one with Z' = 8 and two with Z' = 4) were also discovered in the course of our desired cocrystallization. The inspection of these polymorphs and a previously known polymorph with Z' = 2 revealed that Z' increases as the strength of intermolecular contacts decreases.

Semisynthesis and absolute configuration of a novel rearranged 19,20-δ-lactone (9βH)-pimarane diterpene.

Annonalide (3β,20-epoxy-3α,16-dihydroxy-15-oxo-7-pimaren-19,6β-olide, CHO, 1) is the major (9βH)-pimarane diterpene isolated from tubers of Cassimirella ampla, and it exhibits cytotoxic properties upon interaction with ctDNA. We have prepared new derivatives of 1 by modification of the (9βH)-pimarane backbone and report here the semisynthesis and absolute configuration of a novel rearranged 19,20-δ-lactone (9βH)-pimarane. Our approach was the reduction of the carbonyl groups of 1 with sodium borohydride, at positions C15 (no stereoselectivity) and C3 (stereoselective reduction), followed by rearrangement of the 6,19-γ-lactone ring into the six-membered 19,20-δ-lactone ring in 4a (3β,6β,16-trihydroxy-7-pimaren-19,20β-olide monohydrate, CHO·HO).