The characteristic feature of the solid-state structures of Group 10 iodonium tetracyanidometallates [Ar¹Ar²I]₂[Ni(CN)₄]·CH₂Cl₂ (Ar¹/Ar² = 2,4,6-(MeO)₃C₆H₂/4-NO₂-C₆H₄; 1·CH₂Cl₂), [Ar¹Ar²I]₂[Pd(CN)₄]·MeNO₂ (2·MeNO₂), and [Ar¹Ar²I]₂[Pt(CN)₄]·MeNO₂ (3·MeNO₂) is the presence of M⋯O_NO2 semicoordination between any one of the metal sites and the nitroaryl group. Although there should be a continuum between covalent and noncovalent interactions, both in the geometry and bonding description, we succeeded in identifying the interatomic distances and the corresponding intervals, which are responsible for the covalent (2.0–2.3 Å) and noncovalent (>2.5 Å) bindings of various nitro groups. The geometric parameters of the three structures are in good agreement with the latter range. The noncovalent interactions including M⋯O_NO2 interactions and I⁺⋯NC–M(CN)₃ halogen bonds (HaB) were explored using DFT calculations. Several computational techniques, such as molecular electrostatic potential (MEP) surfaces, QTAIM/NCIplot topological analysis, electron localization function (ELF) analysis, electron density (ED) and electrostatic potential (ESP) profiles analysis (ED/ESP) and energy decomposition analysis (EDA using the Kitaura–Morokuma method) were employed to comprehensively characterize these interactions. Theoretical insights revealed that both M⋯O_NO2 and HaB interactions significantly affect the molecular structures. In-depth examinations using ELF, ED/ESP and EDA methods highlighted the predominant influence of electrostatic effects and confirmed the philicities in the M⋯O interactions. This study is the first that found a place for NO₂-group semicoordination in the entire palette of metal-involving interactions of various nitro groups.

中文翻译：

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硝基和金属离子的相互作用：从配位结合到非共价半配位


10族碘鎓四氰基金属盐的固态结构特征[Ar ¹ Ar ² I] ₂ [Ni(CN) ₄ Cl ₂ (Ar ¹ /Ar ² = 2,4,6-(MeO) ₃ C ₆ H ₂ /4-NO ₂ -C ₆ H ₄ ; 1·CH ₂ Cl ₂ ), [Ar ¹ Ar ² I] ₂ [Pd(CN ) ₄ ]·MeNO ₂ (2·MeNO ₂ ), 和 [Ar ¹ Ar ² I ] ₂ [Pt(CN) ₄ ]·MeNO ₂ (3·MeNO ₂ ) 是 M⋯O < 的存在b28>任一金属位点与硝基芳基之间的半配位。尽管在几何和成键描述中，共价和非共价相互作用之间应该存在连续体，但我们成功地确定了原子间距离和相应的间隔，它们导致了共价（2.0–2.3 Å）和非共价（>2.5 Å） ) 各种硝基的结合。三种结构的几何参数与后一个范围非常吻合。使用 DFT 计算探讨了非共价相互作用，包括 M⋯O _NO2 相互作用和 I ⁺ ⋯NC–M(CN) ₃ 卤素键 (HaB)。多种计算技术，例如分子静电势 (MEP) 表面、QTAIM/NCIplot 拓扑分析、电子局域化函数 (ELF) 分析、电子密度 (ED) 和静电势 (ESP) 剖面分析 (ED/ESP) 以及能量分解分析（使用 Kitaura-Morokuma 方法的 EDA）被用来全面表征这些相互作用。理论见解表明，M⋯O _NO2 和 HaB 相互作用都会显着影响分子结构。 使用 ELF、ED/ESP 和 EDA 方法进行的深入研究强调了静电效应的主要影响，并证实了 M⋯O 相互作用中的亲和性。这项研究首次发现 NO ₂ 基团半配位在各种硝基的金属相互作用的整个调色板中占有一席之地。