A carboxylate-bridged metal-organic coordination polymer ([Ni-2(NA)(4)(mu-H2O)center dot 2H(2)O}(n). (1, HNA = nicotinic acid) has been synthesized under hydrothermal conditions and characterized by FT-IR, TG/DTA, micro analysis and single-crystal X-ray diffraction. 1 has an interesting 3D network structure and adjacent networks are further connected together via strong pi-pi packing interactions. The thermal behavior and catalytic performance of 1 were investigated and its selectivity was measured as 100% for the oxidation of thymol (T) to thymoquinone (TQ). @ 2015 Elsevier Ltd. All rights reserved.