The C-H···metalloaromatic interaction is an of intermolecular contact which is less explored
compared to the common secondary interactions such as hydrogen bonding and π··· π
stacking. A series of 12 palladium(II) xanthate complexes was prepared by varying the
xanthate side group from one carbon to six carbons, i.e. primary, secondary and tertiary
hydrocarbons. All 12 complexes were crystallised and the intermolecular interactions
present in each system were delineated. Among the series, 11 out of 12 palladium(II)
xanthates showed at least one pair of the anticipated C-H···metalloaromatic π interaction,
and up to a maximum of six pairs as identified in Pd[S2CO(neo-hexyl)]2. Further, the CH···metalloaromatic
π interactions led to the formation of zero, one and even two
dimensional motifs in the respective crystals. From a computational chemistry study
performed on Pd[S2CO(n-propyl)]2, it is revealed that a C-H···metalloaromatic π interaction
is of similar strength as intermolecular Pd···S secondary bonding which led to the
dimerisation of palladium(II) xanthate in the condensed phase
