Scientific Activities

Chapter: Aminosilicones as Active Compounds in the Detection and Capture of Co2 from the Environment.

Because anthropogenic carbon dioxide emissions in the atmosphere have greenhouse effect contributing to global warming, worldwide efforts are being made to reduce them, developing techniques for separating and capturing CO2 being a priority. One of the most effective technologies for CO2 capture consists of chemical absorption in a liquid medium containing the amine (alkanolamine, ammonia) with the formation of carbamate or bicarbonate. Because the reaction is reversible, CO2 can then be removed by heating with the amine regeneration and reuse it. Silicone materials have also been studied as means of capturing CO2, among them amino-silicones recently proved to be highly efficient absorber of this. For such use, amines containing siloxanes has several advantages over the classic organic amines, such as high thermal stability, low volatility and low viscosity, which allows their use as such, without the need for dissolution/dilution with water or organic solvents. This makes the heat energy needed to release CO2 and absorber regeneration to be reduced. The effectiveness of the amino-silicones in retaining CO2 is extended in their use as sensors for this gas. This chapter critically reviewed and analyzed the results of the authors and those reported in the literature on both these directions.

Tenth Cristofor I. Simionescu Symposium Frontiers in Macromolecular and Supramolecular Science, Romanian Academy, Bucharest, 8 – 14 June 2018

The Romanian Academy, the "Petru Poni"Institute of Macromolecular Chemistry in Iasi, the Laboratory for Material Structure Research (LRSM) of the University of Pennsylvania (USA) and the National Scenical Foundation - NSF (USA) organized the tenth edition of the International Symposium "Cristofor I. Simionescu" – Frontiers in Macromolecular and Supramolecular Science.This symposium was created in 2008 to celebrate the life and achievements of Professor Christofor I. Simionescu, who was the founding father of Macromolecular Science in Romania and the Director of the ’’Petru Poni’’ Institute of Macromolecular Chemistry in Iasi, Romania, for 30 years (1970–2000). Participating plenary speakers have included the leaders of macromolecular science from the USA, Europe, and Asia. This year the Symposium took place in Bucharest, at the Romanian Academy during 8 and 14 june 2018 and two members of our team participated with one conference – Mirela-Fernanda Zaltariov ’’Versatility of silane/siloxane building blocks in coordination driven self-assembling’’- and one short communication – Georgiana-Oana Turcan-Trofin ’’New ligands and materials developed on silicone substrates’’.

The 21st International Conference on Solid Compounds of Transition Elements, SCTE18, Vienna, March 25 - 29, 2018

Between 25 and 29 March 2018 our team participated at the 21st International Conference on Solid Compounds of Transition Elements, SCTE'2018 that which took place in Vienna, Austria. The SCTE 2018 follows a series of conferences, dating back more than 50 years, with recent meetings in Annecy, France, (2010), Lisboa, Portugal (2012), Genova, Italy, (2014) and Zaragossa, Spain (2016). The SCTE has always been a forum where new ideas and discoveries, related to the solid state chemistry and solid state physics of d- and f-element compounds are presented and discussed. The conference deals with the structure, crystal chemistry, chemical bonding, and magnetic, and electronic transport properties of different classes of intermetallic compounds. Fundamental and applied research in the areas of solid state chemistry, physics and materials science of compounds were included. Our team was represented by Mirela-Fernanda Zaltariov and Georgiana-Oana Turcan-Trofin at the poster session where each presented a poster : ’’Lanthanide-based MOFs built on silicon-containing carboxylate ligands: Synthetic strategies and properties evaluation’’ and ’’Functionalization of siloxane derivatives by attaching polar groups’’ respectively.

A new bis(μ-chlorido) bridged cobalt(II) complex with silyl-containing Schiff-base as catalyst precursor in solvent-free oxidation of cyclohexane.

A new bis(µ-chlorido)-bridged cobalt(II) complex [Co2(µ-Cl)2(HL2)4][CoCl4] (1), where HL2 is a silyl-containing Schiff base, was synthesised. The structure of this compound was established by X-ray crystallography revealing a zwitterionic form adopted by the organic ligand. The temperature dependence of the magnetic susceptibility and the field dependence of the magnetisation indicate the presence of ferromagnetic interactions between paramagnetic d7 cobalt(II) centres (SCo = 3/2). The exchange coupling parameter J(Co1–Co2) = +7.0 cm–1 extracted from broken-symmetry (BS) DFT calculations agrees well with the value of +8.8 cm–1 determined from the experimental data by fitting them with the Hamiltonian math formula. Electrochemical studies indicate that complex 1 is inefficient as a catalyst in electrochemical reduction of protons. One of the reasons is the low stability of the complex in solution. In contrast, 1 acts as an effective homogeneous (pre)catalyst in the microwave-assisted neat oxidation of cyclohexane with aqueous tBuOOH (TBHP). The possible mechanism of catalytic oxidation and other advantages of using 1 in the oxidation of cycloalkanes are discussed.

A five-coordinate manganese(III) complex of a salen type ligand with a positive axial anisotropy parameter D

A new high-spin d4 roughly trigonal-bipyramidal (TBP) manganese(iii) complex with a salen type ligand (H2L), namely MnL(NCS)·0.4H2O, has been synthesised and characterised by elemental analysis, ESI mass spectrometry, IR and UV-vis spectroscopy, and spectroelectrochemistry. X-ray diffraction analysis revealed an axial compression of the approximate TBP. Temperature dependent magnetic susceptibility and variable-temperature variable-field (VTVH) magnetisation measurements, as well as high-frequency and -field EPR (HFEPR) spectroscopy, were used to accurately describe the magnetic properties of this complex and, in particular, determine the spin Hamiltonian parameters: g-values and the zero-field splitting (ZFS) parameters D and E. The HFEPR spectra allowed the extraction of fourth order ZFS parameters. Quantum chemical calculations reproduced well the electronic and geometric structures of this unusual complex and, in particular, its electronic absorption spectrum along with the spin Hamiltonian parameters.