polymers Article Efficient Production of Poly(Cyclohexene Carbonate) via ROCOP of Cyclohexene Oxide and CO2 Mediated by NNO-Scorpionate Zinc Complexes Sonia Sobrino 1, Marta Navarro 2, Juan Fernández-Baeza 1, Luis F. Sánchez-Barba 2,* , Agustín Lara-Sánchez 1 , Andrés Garcés 2 , José A. Castro-Osma 1 and Ana M. Rodríguez 1 1 Centro de Innovación en Química Avanzada (ORFEO-CINQA), Departamento de Química Inorgánica, Orgánica y Bioquímica, Universidad de Castilla-La Mancha, Campus Universitario, 13071 Ciudad Real, Spain;
[email protected] (S.S.);
[email protected] (J.F.-B.);
[email protected] (A.L.-S.);
[email protected] (J.A.C.-O.);
[email protected] (A.M.R.) 2 Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos, Móstoles, 28933 Madrid, Spain;
[email protected] (M.N.);
[email protected] (A.G.) * Correspondence:
[email protected]; Tel.: +34-91-488-8504 Received: 4 September 2020; Accepted: 18 September 2020; Published: 21 September 2020 Abstract: New mono- and dinuclear chiral alkoxide/thioalkoxide NNO-scorpinate zinc complexes were easily synthesized in very high yields, and characterized by spectroscopic methods. X-ray diffraction analysis unambiguously confirmed the different nuclearity of the new complexes as well as the variety of coordination modes of the scorpionate ligands. Scorpionate zinc complexes 2, 4 and 6 were assessed as catalysts for polycarbonate production from epoxide and carbon dioxide with no need for a co-catalyst or activator under mild conditions. Interestingly, at 70 ◦C, 10 bar of CO2 pressure and 1 mol % of loading, the dinuclear thioaryloxide [Zn(bpzaepe)2{Zn(SAr)2}] (4) behaves as an efficient and selective one-component initiator for the synthesis of poly(cyclohexene carbonate) via ring-opening copolymerization of cyclohexene oxide (CHO) and CO2, affording polycarbonate materials with narrow dispersity values.