Electrospray ionization was used to generate species such as [ZnNO3(CH3OH)2]+ from Zn(NO3)2•XH2O dissolved in a mixture of CH3OH and H2O. Collision-induced dissociation of [ZnNO3(CH3OH)2]+ causes elimination of CH3OH to form [ZnNO3(CH3OH)]+. Subsequent collision-induced dissociation of [ZnNO3(CH3OH)]+ causes elimination of 47 mass units (u), consistent with ejection of HNO2. The neutral loss shifts to 48 u for collision-induced dissociation of [ZnNO3(CD3OH)]+, demonstrating the ejection of HNO2 involves intra-complex transfer of H from the methyl group methanol ligand. Subsequent collision-induced dissociation causes the elimination of 30 u (32 u for the complex with CD3OH), suggesting the elimination of formaldehyde (CH2 = O). The product ion is [ZnOH]+. Collision-induced dissociation of a precursor complex created using CH3-18OH shows the isotope label is retained in CH2 = O. Density functional theory calculations suggested that the “rearranged” product, ZnOH with bound HNO2 and formaldehyde is significantly lower in energy than ZnNO3 with bound methanol. We therefore used infrared multiple-photon photodissociation spectroscopy to determine the structures of both [ZnNO3(CH3OH)2]+ and [ZnNO3(CH3OH)]+. The infrared spectra clearly show that both ions contain intact nitrate and methanol ligands, which suggests that rearrangement occurs during collision-induced dissociation of [ZnNO3(CH3OH)]+. Based on the density functional theory calculations, we propose that transfer of H, from the methyl group of the CH3OH ligand to nitrate, occurs in concert with the formation of a Zn–C bond. After dissociation to release HNO2, the product rearranges with the insertion of the remaining O atom into the Zn–C bond. Subsequent C–O bond cleavage, with H transfer, produces an ion–molecule complex composed of [ZnOH]+ and O = CH2.

中文翻译：

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[ZnNO3(CH3OH)2]+解离产生的产物离子的同位素标记和红外多光子光解研究：甲醇转化为甲醛

电喷雾电离用于从溶解在 CH3OH 和 H2O 的混合物中的 Zn(NO3)2•XH2O 生成 [ZnNO3(CH3OH)2]+ 等物质。[ZnNO3(CH3OH)2]+ 的碰撞诱导解离导致 CH3OH 消除，形成 [ZnNO3(CH3OH)]+。随后碰撞诱导的 [ZnNO3(CH3OH)]+ 解离导致 47 个质量单位 (u) 的消除，与 HNO2 的喷射一致。[ZnNO3(CD3OH)]+ 的碰撞诱导解离中性损失转移到 48 u，表明 HNO2 的喷射涉及 H 从甲基甲醇配体的复杂内部转移。随后的碰撞诱导解离导致消除 30 u（与 CD3OH 的复合物为 32 u），表明消除了甲醛（CH2 = O）。产物离子是 [ZnOH]+。使用 CH3-18OH 创建的前体复合物的碰撞诱导解离表明同位素标记保留在 CH2 = O 中。密度泛函理论计算表明，“重排”产物 ZnOH 与结合的 HNO2 和甲醛的能量显着低于结合甲醇。因此，我们使用红外多光子光解光谱来确定 [ZnNO3(CH3OH)2]+ 和 [ZnNO3(CH3OH)]+ 的结构。红外光谱清楚地表明，两种离子都含有完整的硝酸盐和甲醇配体，这表明在碰撞诱导的 [ZnNO3(CH3OH)]+ 解离过程中发生了重排。基于密度泛函理论计算，我们提出 H 从 CH3OH 配体的甲基转移到硝酸盐，与 Zn-C 键的形成同时发生。解离释放出 HNO2 后，产物重新排列，剩余的 O 原子插入到 Zn-C 键中。随后的 C-O 键断裂，伴随着 H 转移，产生由 [ZnOH]+ 和 O = CH2 组成的离子-分子复合物。