Synthesis, Structures, and DFT Study of CuBr Based Coordination Polymers via in Situ Reduction of Copper(II)

This paper describes the one-pot
synthesis of two CuBr based coordination
polymers, {[Cu­(μ2-L1)­Br]·1.87H2O}n (1) and {[Cu­(μ2-L2)­Br]·C4H10O}n (2), where L1 =
2,3-dihydro-5,6-bis­(4-methoxyphenyl)­pyrazine and L2= 5,6-diphenyl-2,3-dihydropyrazine,
upon reduction of copper­(II) at ambient conditions. The structures
have been confirmed by single crystal X-ray diffraction analysis.
Both complexes are found to be highly inert toward oxidation. Finally,
a density functional theory (DFT) study of the energetic features
of several noncovalent interactions observed in the solid state has
been analyzed and characterized using Bader’s theory of “atoms
in molecules” and the cuprophilic interactions in complex 2 using natural bond orbital methodology.