We report the synthesis of a new Mn—PNNP complex ([Mn(P-NH-NH-P)(CO)₂][BPh₄]) with an original approach for the synthesis of a previously reported PNNP ligand PPh₂(o-C₆H₄)NHCH₂CH₂NH(o-C₆H₄)PPh₂ using a new protocol in a less toxic solvent. The PNNP ligand forms a stable mononuclear Mn(I) complex in a low spin state with the additional coordination of two carbonyl groups. This new complex has been characterized by elemental analysis, ¹H, ¹³C and ³¹P NMR spectroscopy, FTIR spectroscopy and HRMS studies. The molecular structure of the complex was determined by X—ray diffraction analysis, which confirmed its distorted octahedral geometry with the linear tetradentate ligand in a rare cis-α-configuration. Additionally, theoretical calculations were performed on the optimized structure of the complex using the functional-basis-set combination B3PW91/6―311++G (d, p)/SDD which showed good correlation with the experimental data. The frontier molecular orbital analysis revealed a large HOMO to LUMO gap (4.66 eV) as expected for a low spin, d⁶ octahedral metal complex with the HOMO concentrated on the Mn center. The Hirschfeld surface analysis signalled the important intermolecular H…H and C…H interactions. A preliminary catalytic study of the complex on transfer hydrogenation of acetophenone was conducted.

我们报道了一种新的 Mn-PNNP 配合物 ([Mn(P-NH-NH-P)(CO) ₂ ][BPh ₄ ]) 的合成，其原始方法用于合成先前报道的 PNNP 配体 PPh ₂ ( o -C ₆ H ₄ )NHCH ₂ CH ₂ NH( o -C ₆ H ₄ )PPh ₂在毒性较小的溶剂中使用新方案。PNNP 配体通过两个羰基的额外配位形成低自旋态的稳定单核 Mn(I) 配合物。这种新配合物已通过元素分析、¹ H、¹³ C 和^{31进行了表征}P NMR 光谱、FTIR 光谱和 HRMS 研究。通过X射线衍射分析确定了该配合物的分子结构，证实了其扭曲的八面体几何形状，其中线性四齿配体呈罕见的顺式-α-构型。此外，利用函数基集组合B3PW91/6―311++G(d，p)/SDD对配合物的优化结构进行了理论计算，与实验数据显示出良好的相关性。前沿分子轨道分析显示 HOMO 与 LUMO 间隙较大 (4.66 eV)，正如低自旋 d ^{6所预期的那样}HOMO 集中在 Mn 中心的八面体金属配合物。Hirschfeld 表面分析表明了重要的分子间 H…H 和 C…H 相互作用。对该配合物对苯乙酮转移氢化反应进行了初步的催化研究。