CAJ | 학술논문

运用M06-2X和ωB97XD方法分别在6-311++G(2d, p)和TZVP基组水平上,对脯氨酸(Pro)的15种构象与Cu、Cu+和Cu2+形成的多种配合物的几何结构、能量学特征、振动光谱和电子结构等进行计算研究.四种水平得到20种[Pro-Cu]、16种[Pro-Cu]+和16种[Pro-Cu]2+稳定结构.[Pro-Cu]和[Pro-Cu]+体系中出现12种Pro构象,而[Pro-Cu]2+体系中出现11种Pro构象,三种体系中最稳定的结构都不是由能量最低的Pro构象生成的.在结构CI3、CI4、CII7和CII8中, Pro的羧基氢转移到亚氨基氮形成两性离子与Cu双配位结合.[Pro-Cu]0/1+/2+体系四种水平计算相对能差范围逐渐增加,结合能分别在-60.0--5.0 kJ?mol-1、-340.0--170.0 kJ?mol-1和-1100.0--860.0 kJ?mol-1范围,配位体系中Pro的变形能逐渐增加. N-H和O-H键伸缩振动频率普遍发生红移,配位体系中部分电荷从Pro转移到Cu上,在[Pro-Cu]2+体系中单配位结构中电荷转移最多,约为单位负电荷.
운용M06-2X화ωB97XD방법분별재6-311++G(2d, p)화TZVP기조수평상,대포안산(Pro)적15충구상여Cu、Cu+화Cu2+형성적다충배합물적궤하결구、능량학특정、진동광보화전자결구등진행계산연구.사충수평득도20충[Pro-Cu]、16충[Pro-Cu]+화16충[Pro-Cu]2+은정결구.[Pro-Cu]화[Pro-Cu]+체계중출현12충Pro구상,이[Pro-Cu]2+체계중출현11충Pro구상,삼충체계중최은정적결구도불시유능량최저적Pro구상생성적.재결구CI3、CI4、CII7화CII8중, Pro적최기경전이도아안기담형성량성리자여Cu쌍배위결합.[Pro-Cu]0/1+/2+체계사충수평계산상대능차범위축점증가,결합능분별재-60.0--5.0 kJ?mol-1、-340.0--170.0 kJ?mol-1화-1100.0--860.0 kJ?mol-1범위,배위체계중Pro적변형능축점증가. N-H화O-H건신축진동빈솔보편발생홍이,배위체계중부분전하종Pro전이도Cu상,재[Pro-Cu]2+체계중단배위결구중전하전이최다,약위단위부전하.
The geometric and electronic structures, energetics, and vibrational frequencies of different coordinate systems formed between 15 conformers of proline (Pro) and Cu, Cu+, and Cu2+were investigated in detail, using the M06-2X andωB97XD methods with 6-311++G(2d, p) and TZVP basis sets. A total of 20, 16, and 16 stable [Pro-Cu]0/1+/2+complexes were obtained at four levels. These structures demonstrated that 12 conformers of Pro exist in the [Pro-Cu] and [Pro-Cu]+systems, while 11 conformers are present in the [Pro-Cu]2+complexes. The most stable complexes are evidently not formed by the lowest energy conformer of Pro with Cu, Cu+, and Cu2+. In the CI3, CI4, CII7, and CII8 complexes, the carboxyl group hydrogen of Pro was found to transfer to the imino nitrogen to form a zwitterion. Both the relative energy difference and the deformation energy of Pro gradual y increase along with the charge number of the Cu. The binding energies of the [Pro-Cu]0/1+/2+systems were determined to be in the ranges of-60.0 to-5.0,-340.0 to-170.0, and-1100.0 to-860.0 kJ?mol-1, respectively. The stretching vibrational frequencies of the N-H and O-H bonds in Pro all exhibit a general red shift on complexation. Additional y, each system shows charge transfer from the Pro to the Cu, even in the case of [Pro-Cu]2+, some complexes that have more than one negative charge.