Structural insights into a versatile macrocyclic family based on 2,5-diphenyl[1,3,4]oxadiazole: a combined X-ray diffraction and computational study

By means of X-ray diffraction analysis the solid state structure of the diprotonated species of the ligand L1_Me (9,12-Dimethyl-9,12,27,28-tetraaza-15,18-dithia-29-oxatetracyclo[24.2.1.02,7.020,25]-enneicosa-2,4,6,20,22,24,26,281-octaene), a macrocycle containing a mixed sulfur-nitrogen set of donor atoms decorated with the PPD signaling group, and of its dinuclear platinum complex was investigated. The information retrieved were used as starting point for a deep computational study. Then, with the aim to get hints for the design of possibly improved strictly related receptors, the molecular modeling study was extended to the all-nitrogen ligand L2_H which, at variance with L1_Me, has four nitrogen atoms as donors. Finally, to complete the modeling investigation we design the related ligands L1_H, L2_Me and L3_H on which computational studies were performed. The aim was to investigate and try to rationalise the parameters affecting the overall shape of the host-guest adducts.