1. School of Chemical SciencesUniversiti Sains Malaysia Malaysia
2. Department of ChemistryKano University of Science and Technology Wudil Kano Nigeria
3. Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong ProvinceShantou University Shantou 515063 China
4. Department of Chemistry, Faculty of ScienceUniversiti Malaya Kuala Lumpur Malaysia