Syntheses, X-ray Crystal Structures, Photoluminescence Properties, Antimicrobial Activities and Hirshfeld Surface of Two New Cd(II) Azide/Thiocyanate Linked Coordination Polymers

The reaction of cadmium(II) acetate salts with multisite coordinated compartmental Schiff base ligand N,N'-Bis(3-methoxysalicylidenimino)-1,3-diaminopropane (H2L1) in presence of co-lingand azido/thiocyanato afforded two new coordination polymers {[Cd-4(N-3)(4)(L-1)(2)]H2O}(n) (1), [Cd-4(SCN)(4)(L-1)(2)](n) (2). The obtained compounds, 1 and 2 are 1D and 2D coordination polymers respectively and they have been characterized by IR spectroscopy, UV-vis spectroscopy, elemental analysis, and single-crystal X-ray diffraction. The variation in the extended forms of 1 and 2 is governed by the kind of co-ligands utilized in the reaction. The complete structural study reveals that, in both cases the fully deprotonated ligand [L-1](2-) has utilized all six potential coordination sites to hold a pair of Cd(II) ions. Moreover, [N-3](-) in 1 is coordinating to metal atom by both trans end-to-end (EE mu-1,3) and end-on (EO or mu-1,1) mode and [SCN](-) is showing only end-to-end (EE mu-1,3) coordination mode in 2. The photo luminescent properties and antimicrobial activities of the compounds 1 and 2 were investigated and discussed in details. Upon irradiation with UV light Cd(II) polymeric compounds 1-2 exhibit deep blue emissions of 448-451 nm subjected to dimethyl sulfoxide solution due to pi ->pi* intraligand fluorescence. Apart from, as a complementary revelation, intermolecular interactions with respect to percentages of hydrogen bonding in the crystal structures of two Cd(II) polymeric compounds were quantified by Hirshfeld surface and fingerprint plots analysis.