The Na[3,3’-Fe(8-I-1,2-C2B9H10)2] and Na[2,2’-M(1,2-C2B9H11)] (M= Co3+, Fe3+), small molecules are synthesized and the X-ray structures [(H3O)(H2O)5][2,2’-Co(1,7-C2B9H11)2] and [Cs(MeCN)[8,8’-I2-Fe(1,2 C2B9H10)2], both displaying transoid conformation of [M(C2B9)2]- framework, are reported. Importantly, the...

With the goal to produce molecules with high electron accepting capacity and low reorganization energy upon gaining one or more electrons, a synthesis procedure leading to the formation of a B-N(aromatic) bond in a cluster has been developed. The research was focused on the development of a molecular structure able to accept and release a specific number of electrons without decomposing or change in its structural arrangement. The synthetic procedure consists of a parallel decomposition reaction to generate a reactive electrophile and a synthesis reaction to generate the B-N(aromatic) bond. This procedure has paved the way to produce the metallacarboranylviologen [M(CBH)(CBH)-NCH-CHN-M'(CBH)(CBH)] (M = M' = Co, Fe and M = Co and M' = Fe) and semi(metallacarboranyl)viologen [3,3'-M(8-(NCH-CHN-1,2-CBH)(1',2'-CBH)] (M = Co, Fe) electron cumulative molecules. These molecules are able to accept up to five electrons and to donate one in single electron steps at accessible potentials and in a reversible way. By targeted synthesis and corresponding electrochemical tests each electron transfer (ET) step has been assigned to specific fragments of the molecules. The molecules have been carefully characterized, and the electronic communication between both metal centers (when this situation applies) has been definitely observed through the coplanarity of both pyridine fragments. The structural characteristics of these molecules imply a low reorganization energy that is a necessary requirement for low energy ET processes. This makes them electronically comparable to fullerenes, but on their side, they have a wide range of possible solvents. The ET from one molecule to another has been clearly demonstrated as well as their self-organizing capacity. We consider that these molecules, thanks to their easy synthesis, ET, self-organizing capacity, wide range of solubility, and easy processability, can find important application in any area where ET is paramount.

Slow-spin relaxation through Raman and direct mechanisms of a low-spin S = 1/2 FeIII carborane complex with the metal directly coordinated to the carborane ligand.

Although a variety of cancers is initially susceptible to chemotherapy, they eventually develop multi-drug resistance. To overcome this situation, more effective and selective treatments are necessary by using anti-tumour agents...

We report the synthesis and X-ray characterization of the N 6 -benzyl-N 6methyladenine ligand (L) and three metal complexes, namely [Zn(HL) Cl 3 ]·H 2 O (1), [Cd(HL) 2 Cl 4 ] (2) and [H 2 L] 2 [Cd 3 (μ-L) 2 (μ-Cl) 4 Cl 6 ]·3H 2 O (3). Complex 1 consists of the 7H-adenine tautomer protonated at N3 and coordinated to a tetrahedral Zn(II) metal centre through N9. The octahedral Cd(II) in complex 2 is N 9 -coordinated to two N 6 -benzyl-N 6 -methyladeninium ligands (7H-tautomer protonated at N3) that occupy apical positions and four chlorido ligands form the basal plane. Compound 3 corresponds to a trinuclear Cd(II) complex, where the central Cd atom is six-coordinated to two bridging μ-L and four bridging μ-Cl ligands. The other two Cd atoms are six-coordinated to three terminal chlorido ligands, to two bridging μ-Cl ligands and to the bridging μ-L through N3. Essentially, the coordination patterns, degree of protonation and tautomeric forms of the nucleobase dominate the solid-state architectures of 1-3. Additionally, the hydrogen-bonding interactions produced by the endocyclic N atoms and NH groups stabilize high-dimensional-order supramolecular assemblies. Moreover, energetically strong anion-π and lone pair (lp)-π interactions are important in constructing the final solid-state architectures in 1-3. We have studied the non-covalent interactions energetically using density functional theory calculations and rationalized the interactions using molecular electrostatic potential surfaces and Bader's theory of atoms in molecules. We have particularly analysed cooperative lp-π and anion-π interactions in 1 and π + -π + interactions in 3.

Among all compounds described here, compound 8, bearing a 7-chloro-4N-methyl-p-chloroaniline quinolinium moiety, exhibited the greatest inhibitory activity at the enzyme (IC = 0.29 μM) and antiproliferative activity in cellular assays (GI = 0.29-0.92 μM). Specifically, compound 8 strongly induces a cell-cycle arrest in G1 phase, but it does not significantly induce apoptosis while causing senescence in the MDA-MB-231 cell line.

An electrophilic substitution on metallacarboranes by using a stabilized carbocation that can be made in situ is reported for the first time. This new synthetic methodology provides a new perspective on easy metallacarborane derivatization with organic fragments, which enhances the properties of both fragments and widens their possible applications. † Electronic supplementary information (ESI) available. See

The relatively low symmetry of [3,3′-Co(1,2-C 2 B 9 H 11 ) 2 ] − ([ 1 ] − ), along with the high number of available substitution sites, 18 on the boron atoms and 4 on the carbon atoms, allows a fairly regioselective and stepwise chlorination of the platform and therefore a very controlled tuning of the electrochemical potential tuning. This is not so easily found in other systems, e.g., ferrocene. In this work, we show how a single platform with boron and carbon in the ligand, and only cobalt can produce a tuning of potentials in a stepwise manner in the 1.3 V range. The platform used is made of two icosahedra sharing one vertex. The E 1/2 tuning has been achieved from [ 1 ] − by sequential chlorination, which has given potentials whose values increase sequentially and linearly with the number of chloro groups in the platform. [ Cl 8 -1 ] − , [ Cl 10 -1 ] − , and [ Cl 12 -1 ] − have been obtained, which are added to the existing [ Cl-1 ] − , [ Cl 2 -1 ] − , [ Cl 4 -1 ] − , and [ Cl 6 -1 ] − described earlier to give the 1.3 V range. It is envisaged to extend this range also sequentially by changing the metal from cobalt to iron. The last successful synthesis of the highest chlorinated derivatives of cobaltabis(dicarbollide) dates back to 1982, and since then, no more advances have occurred toward more substituted metallacarborane chlorinated compounds. [ Cl 8 -1 ] − , [ Cl 10 -1 ] − , and [ Cl 12 -1 ] − are made with an easy and fast method. The key point of the reaction is the use of the protonated form of [Co(C 2 B 9 H 11 ) 2 ] − , as a starting material, and the use of sulfuryl chloride, a less hazardous and easier to use chlorinating agent. In addition, we present a complete, spectroscopic, crystallographic, and electrochemical characterization, together with a study of the influence of the chlorination position in the electrochemical properties.