Preparation, Structure, and Characterization of Nickel(II)Complexes Bearing Amino-LinkedN-Heterocyclic Ligands

• Main Authors: Yi-ping Huang, 黃意評
• Other Authors: none
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/75159909156705357490

碩士 === 國立臺灣科技大學 === 工程技術研究所 === 97 === To removed 1 equiv HBr from the imidazolium salt 2 by a strong base NaOH afford compound 3. Compound 3 has better organic solubility than 2 can make it have better reactivity with organometallic reagents (NaN(TMS)2, LiN(TMS)2) to afford free carbene 4 and LiBr carbene 5 by a mild condition. The mono and bis nickel NHCMES complexes 6-Br and 7-Br are preparing by a carbene transfer agent 5 reacted with Ni(PPh3)2Br2, through controlling the stoichlometric equiv of NHC. The similar preparation can afford to mono 6-Cl and bis 7-Br by free carbene and Ni(PPh3)2Cl2. The single-crystal x-ray structures of 7 show that they are syn-trans forms and with a square planar nickel center, proton NMR demonstrated the isomerization process in solution of 7 does not possess a solvent-induced cis/trans isomers, but rather they are in syn/anti equilibrium. This phenomenon was further confirmed by the computation calculation. The crystal packing of 7 exhibits a 2D-supramolecular with cavity, especially 7-Cl filled with water in cavity. To replace a halide from 7 with non-coordinating anion (OTf-, BF-) to observe the reaction products’ crystal packing is interesting to us. Although the 11 and 12 crystals packing without have 2D-supramolecular and cavity. On the other hand, to synthesis a Ni(I) NHCMES complexes is a special experience to us. In conclusion, we have developed a series of nickel(II) complexes and further to research its characteristics.