Three cis-MoO2 complexes [MoO2(CAB)(py)] (1), [MoO2(CAB)(3-pic)] (2) and [MoO2(CAB)(4-pic)] (3) which vary in the nature of the heterocyclic bases in the auxiliary coordination site derived from an ONO donor aroylhydrazone (H2CAB) have been synthesized and characterized by various physicochemical methods. The single-crystal X-ray diffraction studies reveal that the complexes adopt a distorted octahedral N2O4 coordination sphere around the Mo(VI) center in which the ONO donor atoms of hydrazone moiety and one oxido oxygen constitute the NO3 basal plane and the axial position by the other oxido oxygen and nitrogen atom of coordinated pyridine molecule in [MoO2(CAB)(py)] (1) or picoline molecule in [MoO2(CAB)(3-pic)] (2) and [MoO2(CAB)(4-pic)] (3). The hydrogen bonding interaction generates a two-dimensional supramolecular sheet-like architecture in [MoO2(CAB)(py)] (1) and [MoO2(CAB)(3-pic)] (2), whereas a three-dimensional network was observed in [MoO2(CAB)(4-pic)] (3). The interaction energy calculations reveal that the dispersion energy component dominates over other components and [MoO2(CAB)(3-pic)] (2) is found to be energetically more stable. Furthermore, the aroylhydrazone shows free radical scavenging activity, whereas the complexes are inactive.

中文翻译：

---

含有吡啶或甲基吡啶作为辅助配体的钼 (VI) 配合物的光谱研究和晶体结构：相互作用能计算和自由基清除研究

三种顺式 MoO2 复合物 [MoO2(CAB)(py)] (1)、[MoO2(CAB)(3-pic)] (2) 和 [MoO2(CAB)(4-pic)] (3)，它们在来自 ONO 供体芳酰腙 (H2CAB) 的辅助配位位中的杂环碱基的性质已被合成并通过各种物理化学方法进行表征。单晶X射线衍射研究表明，配合物在Mo（VI）中心周围采用扭曲的八面体N2O4配位球，其中腙部分的ONO供体原子和一个氧化氧构成NO3基面和轴向位置[MoO2(CAB)(py)] (1) 中配位吡啶分子或 [MoO2(CAB)(3-pic)] (2) 和 [MoO2(CAB)(4) 中甲基吡啶分子的另一个氧化氧和氮原子-pic)] (3). 氢键相互作用在 [MoO2(CAB)(py)] (1) 和 [MoO2(CAB)(3-pic)] (2) 中产生二维超分子片状结构，而三维网络则是在 [MoO2(CAB)(4-pic)] (3) 中观察到。相互作用能计算表明，色散能分量比其他分量占主导地位，并且发现 [MoO2(CAB)(3-pic)] (2) 在能量上更稳定。此外，芳酰腙显示自由基清除活性，而配合物是无活性的。