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过渡金属离子的d—电子特性,使得它们的络合物可以在很多有机合成反应中起催化作用,含三苯磷配体的反式铂氢络合物就是一种稳定的、广泛应用的催化剂。为此,本工作合成了反式—[PtHXL_2],L=PPh_3,X=Cl~-、Br~-、I~-、NO_3~-、NO_2~-、NCS~-六种铂络合物,并测定了其~1H—NMR谱。实验获得该络合物系列中,与铂(Ⅱ)相连的质子在高场具有较大的化学位移,即δ_H=-12～-24ppm和很大的铂-氢偶合常数即J_(pt-H)=900—1400Hz,以及磷氢偶合常数即J_(p-H)≈15Hz。此外,还研究了配体对铂-氢的~1H化学位移及铂-氢偶合常数;铂-氢键长对铂-氢的~1H化学位移的影响,并找出了一定的规律性。从而得到了络合物的顺反异构,键合异构及电子密度分布的有关信息。关于铂络合物的核磁共振研究,虽有过报道,但配体为三苯膦的反式-[PtH(PPh~3)_2]系列络合物NMR研究,尚未见报道。
The d-electronic properties of transition metal ions allow their complexes to act as a catalyst in many organic synthesis reactions. The trans-platinum hydrogen complexes containing triphenylphosphine ligands are a stable and widely used catalyst . In this work, six platinum complexes of trans- [PtHXL_2], L = PPh_3, X = Cl ~ -, Br ~ -, I ~ -, NO_3 ~ -, NO_2 ~ The ~ 1H-NMR spectrum was measured. In the series of experiments, the proton attached to platinum (Ⅱ) has a large chemical shift at high field, ie, δ_H = -12 ~ -24ppm and a large platinum-hydrogen coupling constant, J_ (pt-H ) = 900-1400 Hz, and the pH of the hydrogen-hydrogen coupling J J (pH) ≈ 15 Hz. In addition, the ~ 1H chemical shifts and platinum-hydrogen coupling constants of platinum-hydrogen ligands were also studied. The influence of platinum-hydrogen bond length on the ~ 1H chemical shift of platinum-hydrogen was also studied and a certain regularity was found out. The cis- and trans-isomers, the bonding isomers and the electronic density distribution of the complexes were obtained. Although studies on NMR of platinum complexes have been reported, NMR studies on the complexes of trans - [PtH (PPh ~ 3) _2] with triphenylphosphine have not been reported yet.