Soluble Molybdenum(V) Imido Phthalocyanines and Pyrazinoporphyrazines: Crystal Structure, UV–vis and Electron Paramagnetic Resonance Spectroscopic Studies

Soluble alkyl and aryl imido phthalocyanines [Pc#Mo­(NR)­Cl] (R = tBu, Mes) with molybdenum­(V) as central metal were prepared and studied by UV–vis and electron paramagnetic resonance (EPR) spectroscopy. As structural analogue to the weakly aggregating, soluble alkyl substituted Pc# ligand, a new, more electron deficient octaazaphthalocyanine, the pyrazinoporphyrazine ligand Ppz#, was designed. The respective alkyl and aryl imido complexes [Ppz#Mo­(NR)­Cl] are the first examples of molybdenum pyrazinoporphyrazines. UV–vis and EPR spectra revealed unexpected differences between the alkyl and the aryl imido complexes, indicating different electronic structures depending on the nature of the axial ligand. The octahedral coordination of the molybdenum atoms by the axial NR and Cl ligands and the equatorial macrocycles could be verified by EPR spectroscopy. This result was also confirmed by the crystal structure of [Pc#Mo­(NMes)­Cl], which crystallizes from CH2Cl2 in the cubic space group Im3̅.以钼(V)为中心金属的可溶性烷基与芳基酰亚胺基酞菁配合物[Pc#Mo(NR)Cl]（R = 叔丁基(tBu)、均三甲苯基(Mes)）已被合成，并通过紫外-可见（UV–vis）光谱与电子顺磁共振（EPR）光谱开展表征研究。作为弱聚集、可溶性烷基取代酞菁(Pc#)配体的结构类似物，我们设计了一种新型缺电子八氮杂酞菁类配体——吡嗪并卟啉嗪(Ppz#)。对应的烷基与芳基酰亚胺基配合物[Ppz#Mo(NR)Cl]为首例钼基吡嗪并卟啉嗪配合物。紫外-可见与EPR光谱揭示了烷基与芳基酰亚胺基配合物间存在未预期的光谱差异，表明其电子结构会随轴向配体的性质发生改变。通过EPR光谱可证实，钼原子由轴向NR与Cl配体以及赤道大环配体配位形成八面体结构。该结果也得到了[Pc#Mo(NMes)Cl]晶体结构的验证：该配合物从二氯甲烷(CH₂Cl₂)中结晶，所属空间群为立方空间群Im3̅。