Whereas harnessing non-covalent interactions (NCIs) have largely been applied to late-transition metal complexes and to the corresponding catalytic reactions, there are very few examples showing the importance of NCIs in early-transition metal and main group metal catalysis. Here, we report on the effects of hydrogen bond donors in the catalytic pocket to explain the high activity and stereoselectivity of a series of aluminium catam complexes in rac-lactide ring-opening polymerisation (ROP). Four original aluminium catam catalysts have been synthetized and fully characterized. Structure-activity relationships and isotope effect show the importance of the NH moieties of the ligand in rac-lactide ROP. Computational studies highlight beneficial hydrogen bonds between the ligand and the monomer. Overall, structural characterization of the catalysts, mechanistic, kinetic and computational studies support the benefits of non-covalent interactions in the catalytic pocket.

Theory of Random Matrix Ensembles have proven to be a useful tool in the study of the statistical distribution of energy or transmission levels of a wide variety of physical systems. We give an overview of certain q-generalizations of the Random Matrix Ensembles, which were first introduced in connection with the statistical description of disordered quantum conductors.

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We consider an entire function f , bounded on every my but not constant, and define for every complex A, We show that G(A) is holomorphic on Ce if and only if f is bounded in a sectore -& c argz < 6 ' + E. Otherwise G has singularities at all points of Cv.