The W-C bonds have not only (CO)5W C(ECp*)2 strong -donation but also a significant contribution π-donation and the trend of the W-C bond strength in W5-C1E complexes. EDA-NOCV calculations reveal that C(ECp*)2 ligands in W5-C1E complexes are strong -donors and weak -donors which make them good spectator ligands that are well-suited for synthesizing robust catalysts for a variety of applications. | Vietnam Journal of Chemistry, International Edition, 55(5): 561-568, 2017 DOI: Structure and chemical bond of carbodiylide complexes [W(CO)5{C(ECp*)2}] (E = B to Tl): DFT calculations Nguyen Thi Ai Nhung Department of Chemistry, Hue University of Sciences, Hue University, Hue, Vietnam Received 2 March 2017; Accepted for publication 20 October 2017 Abstract The bonding of the carbodiylide complexes [(CO)5W-{C(ECp*)2}] (W5-C1E) was calculated at the BP86 level with the basis sets def2-SVP, def2-TZVPP, and TZ2P+. The nature of the (CO)5W-{C(ECp*)2} bonds was analyzed by energy decomposition method. The calculated structures of complexes show that all ligands C(ECp*) 2 (C1E) are bonded in a tilted orientation relative to the fragment W(CO) 5 in W5-C1E and the tilting angle become much more acute when E becomes heavier. Analysis of the bonding reveals that [(CO)5W–{C(E’Cp*)2}] donation in W5-C1B come from the -lone-pair orbital of C(BCp*)2, while [(CO)5W–{C(E’Cp*)2}] donation in the strongly tilted bonded complexes when E’ = Al to Tl comes from the -lone-pair orbital of the carbodiylides C(E’Cp*) 2. The W-C bonds have not only (CO)5W C(ECp*)2 strong -donation but also a significant contribution π-donation and the trend of the W-C bond strength in W5-C1E complexes. EDA-NOCV calculations reveal that C(ECp*)2 ligands in W5-C1E complexes are strong -donors and weak -donors which make them good spectator ligands that are well-suited for synthesizing robust catalysts for a variety of applications. Keywords. Carbodiylides, energy decomposition analysis, bond dissociations energy, bonding analysis. 1. INTRODUCTION The recent experimental studies of main-group elements pentamethylcyclopentadienyl (Cp*) suggested that the steric requirements of the - or bound Cp* group enable the kinetic stabilization of highly reactive species and represents a very important substituent [1]. Moreover, the chemistry of Cp* with transition metal complexes .