This article provides a third manifestation of a new tradition by which the editors of Comments on Inorganic Chemistry wish to lead by example, whereby we start publishing original research content that, nonetheless, preserves the journal’s identity as a niche for “critical discussion” of contemporary literature in inorganic chemistry. (For the first and second manifestations, see: (1) Otten, B. M.; Melancon, K. M.; Omary, M. A. “All that Glitters is Not Gold: A Computational Study of Covalent vs Metallophilic Bonding in Bimetallic Complexes of d¹⁰ Metal Centers: A Tribute to Al Cotton on the 10th Anniversary of His Passing,” Comments Inorg. Chem. 2018, 38, 1–35; (2) Yaseen, W. K.; Sanders, S. F.; Almotawa, R. M.; Otten, B. M.; Bhat, S.; Alamo, D. C.; Marpu, S. B.; Golden, T. D.; Omary, M. A. “Are Metal Complexes ‘Organic’, ‘Inorganic’, ‘Organometallic’, or ‘Metal-Organic’ Materials? A Case Study for the Use of Trinuclear Coinage Metal Complexes as ‘Metal-Organic Coatings’ for Corrosion Suppression on Aluminum Substrates,” Comments Inorg. Chem. 2019, 39, 1–26.) Herein, we contrast the electronic structure of two categories of Pt(II) complexes with mixed imine/thiolato ligands: a new class of [Pt(N^N)₂(S^S)] bis(κ¹-diimine)dithiolatoplatinum(II) divergent complexes—whereby only one N atom from the “back-to-back” diimine ligand actually coordinates to a Pt(II) center in a non-bridging monodentate manner—vis-à-vis the hitherto well-studied [Pt(N^N)(S^S)] (κ²-diimine)dithiolatoplatinum(II) convergent congeners—whereby both the diimine and dithiolate coordinate as κ²-chelating bidentate. Thus, in pursuit of using luminescent building blocks to generate light-harvesting supramolecular coordination compounds, we report the synthesis, characterization, and reactivity of Pt(pyz)₂(mnt), 1, in high yield (pyz = pyrazine, mnt = maleonitriledithiolate). The complex exhibits solvent-dependent exchange of the pyrazine ligands, which can be utilized in the formation of larger complexes containing platinum dithiolate moieties. As proof of concept, 1 has been converted into the more inert Pt(4,4ʹ-bpy)₂(mnt), 2, and Pt(4-ap)₂(mnt), 3, (4-ap = 4-aminopyridine) complexes. These complexes exhibit redox properties, are strong absorbers of ultraviolet and visible light, and exhibit bright-luminescence at 77 K. Single-crystal X-ray diffraction analysis for 1 and 3 confirms the monotopic coordination of the ligands with intramolecular Pt-S and Pt-N bond lengths being comparable to other complexes of type (κ²-diimine)(dithiolate)Pt(II), whereas significant torsion is exhibited by the two heterocyclic rings due to the lack of tethering to one another. Solvent-dependent stability is uncovered for 1 crystals, whereas the crystal structure of 3 reveals an interesting supramolecular quadrangle resulting from hydrogen bonding between the amine groups of two complexes and two interstitial water molecules. A commentary is presented to contrast the electronic structure of the divergent complexes herein with that of a diimine-dithiolate analogue. Experimentally, the luminescence is believed to be sensitized in the new class of divergent complexes, given that their lack of conjugation of two aromatic rings renders them less-efficient π-acceptors compared to analogous diimines such as 2,2ʹ-bipyridine (2,2ʹ-bpy), hence blue-shifting the absorption toward the blue/near-UV and assisting in keeping the emission well within the visible region, whereby energy gap law considerations would suppress quenching effects in the red/near-infrared regions, especially under experimental conditions conducive for phosphorescence and aggregation effects in the solid state and higher-concentration fluid and/or frozen solutions. Computational studies for monomeric models of the three divergent complexes plus the diimine-dithiolate congener, Pt(2,2ʹ-bpy)(mnt), attain reasonable agreement with experimental structural, spectroscopic, and redox properties and provide excellent insights for the comparison between the two categories of complexes upon which we focus the commentary section. The computed photophysical properties reveal phosphorescence due to higher-lying triplet states, as the T₁ is found to luminesce in the near-IR region and entail a ligand-field (dd) transition origin, whereas higher-lying states are shown to be in the visible region, close to experimental phosphorescence energies, and are consistent with the expected charge transfer transition to imine/diimine lowest-unoccupied molecular orbitals (LUMOs) from admixed dithiolate/platinum highest-occupied molecular orbitals (HOMOs). The T₁ state is likely the culprit for the vanishing emission intensity at ambient temperature for both classes of complexes. We also find that both the T₁ and D₁ states for the neutral exciton and radical polaron (anion or cation) species, respectively, are severely distorted in 1–3 vs Pt(2,2ʹ-bpy)(mnt) models. Near-perfect orthogonality of the two heterocyclic rings can be attained for such excited and redox models of Pt(κ¹-imine)₂(dithiolate), whereas this distortion is hindered in Pt(κ²-diimine)(dithiolate) models due to the steric constraint in their CCNNPt metallacycle.

本文提供了新传统的第三种表现形式，《无机化学评论》的编辑希望以身作则，由此我们开始发表原始研究内容，但仍保留该期刊作为当代“批判性讨论”的利基地位。无机化学文献。（关于第一和第二种表现，请参见：（1）BM的Otten； KM的Melancon；马萨诸塞州的Omary“所有闪闪发光的东西都不是金：d ^10个金属中心的双金属配合物中共价键与亲金属键的计算研究：A悼念铝棉对他的逝世十周年之际，”评论Inorg。化学。2018，38，1–35; （2）Yaseen，WK；旧金山的桑德斯；马萨诸塞州阿尔莫塔瓦；奥特姆（BM）；Bhat，S .; 哥伦比亚特区阿拉莫; SB，马普；TD，金色；马萨诸塞州奥马里“金属络合物是'有机'，'无机'，'有机金属'或'金属有机'材料吗？使用三核可铸金属配合物作为“金属有机涂层”以抑制铝基底腐蚀的案例研究，” Inorg评论。化学。2019，39，1-26）在此，我们对比两类Pt中的电子结构（II）配合物具有混合亚胺/ thiolato配体：一类新的[PT（N ^ N）₂（S ^ S）]双（κ ¹-diimine）dithiolatoplatinum（II）不同的配合物，相对于迄今为止，只有一个“ N-背对背”二亚胺配体中的N原子实际上以非桥接单齿方式与Pt（II）中心配位。充分研究[PT（N ^ N）（S ^ S）]（κ ²二亚胺）dithiolatoplatinum（II）会聚同源-由此两个二亚胺和二硫醇坐标作为κ ² -chelating二齿。因此，在追求使用发光结构单元生成光捕获超分子配位化合物时，我们报道了Pt（pyz）₂的合成，表征和反应性（mnt），1，高收率（pyz =吡嗪，mnt =顺丁烯二腈）。该配合物表现出吡嗪配体的溶剂依赖性交换，其可用于形成包含二硫醇铂部分的较大的配合物。作为概念证明，已将1转换为更惰性的Pt（4,4ʹ-bpy）₂（mnt）2和Pt（4-ap）₂（mnt）3，（4-ap = 4-氨基吡啶）复合体。这些配合物表现出氧化还原特性，是紫外线和可见光的强吸收剂，并在77 K下表现出明亮的发光。1和3的单晶X射线衍射分析证实分子内Pt-S和Pt-N键长的配体的单位配位可与（κ2-^二亚胺）（二硫代）Pt（II）型的其他配合物相比较，而两个杂环显示出显着的扭转缺乏彼此的束缚。发现了1种晶体的溶剂依赖性稳定性，而3种晶体的晶体结构揭示了一个有趣的超分子四边形，它是由两个配合物和两个间隙水分子的胺基之间的氢键形成的。提出评论以对比本文发散复合物的电子结构与二亚胺-二硫代硫酸盐类似物的电子结构。在实验上，人们认为这种发光在新一类的发散配合物中是敏感的，因为与类似的二亚胺如2,2′-联吡啶（2,2′）相比，它们缺乏两个芳香环的共轭使它们的π-受体效率较低。 -bpy），从而使吸收向蓝移至蓝/近紫外，并有助于将发射良好地保持在可见光区域内，从而能隙定律的考虑会抑制红/近红外区的猝灭效果，特别是在有利于固态和高浓度流体和/或冷冻溶液的磷光和聚集效应的实验条件下。对三个发散配合物加上二亚胺二硫代同类物Pt（2,2ʹ-bpy）（mnt）的单体模型的计算研究，与实验结构，光谱和氧化还原性质取得了合理的一致，并为两者之间的比较提供了极好的见解。我们将评论部分集中在两类复合体上。所计算的光物理性质揭示了由于较高的三重态导致的磷光，如T 对三个发散配合物加上二亚胺二硫代同类物Pt（2,2ʹ-bpy）（mnt）的单体模型的计算研究与实验结构，光谱和氧化还原性质达成合理的一致，并为两者之间的比较提供了极好的见解。我们将评论部分集中在两类复合体上。所计算的光物理性质揭示了由于较高的三重态导致的磷光，如T 对三个发散配合物加上二亚胺二硫代同类物Pt（2,2ʹ-bpy）（mnt）的单体模型的计算研究与实验结构，光谱和氧化还原性质达成合理的一致，并为两者之间的比较提供了极好的见解。我们将评论部分集中在两类复合体上。所计算的光物理性质揭示了由于较高的三重态导致的磷光，如T发现₁在近红外区域发光，并伴随有配体场（dd）跃迁原点，而较高的态显示在可见光区域，接近实验磷光能量，并且与预期电荷一致从混合的二硫醇盐/铂最高占据分子轨道（HOMO）转移到亚胺/二亚胺最低未占据分子轨道（LUMO）。对于两种配合物，T ₁状态可能是环境温度下发射强度消失的罪魁祸首。我们还发现，中性激子和自由基极化子（阴离子或阳离子）物种的T ₁和D ₁状态在1-3中都严重失真。vs Pt（2,2ʹ-bpy）（mnt）模型。可以实现为铂的这种激发和氧化还原模型（κ两个杂环的近乎完美的正交性¹ -亚胺）₂（二硫醇），而这畸变是铂受阻（κ ²二亚胺）（二硫醇盐）模型由于CCNNPt金属环中的空间限制。