Exploiting the kinetic domain provided by hydrothermal conditions, it was possible to isolate three transient metastable crystal structures, each bearing concomitant pairs of octamolybdate isomers, namely, α–β, γ–β or β_cs–β_gp stabilized by distinctive homoleptic [Co(bpy)₃]ⁿ⁺ (bpy = 2,2′‐bipyridine; n = 2 or 3) cations generated in situ: [Co(bpy)₃]₄[(α‐Mo₈O₂₆)(β‐Mo₈O₂₆)]·5H₂O (1), [NH₄][Co(bpy)₃][(γ‐Mo₈O₂₆)_0.5(β‐Mo₈O₂₆)_0.5]·4H₂O (2) and [Co(bpy)₃]₂[(β_cs‐Mo₈O₂₆)_0.5(β_gp‐Mo₈O₂₆)]·12H₂O (3). Solid 1 with the space group P2₁/n and unit‐cell parameters a = 22.160 (6), b = 14.209 (3), c = 24.641 (4) Å, β = 99.10 (2)° and V = 7661 (3) ų resulted in the same crystal structure as that synthesized previously under different conditions by Sun et al. [J. Mol. Struct. (2005), 741, 149–153]. Factors directing the reaction, such as product composition and phase stability, were monitored by analysis of the PXRD patterns of the bulk solids obtained under different experimental conditions. The relative proportions of the mixed phases 1–3 or their stabilization are highly dependent on the initial Co:Mo molar ratio and the reaction temperature. In particular, an increase in temperature induces the transformation of 1–3 into more thermodynamically stable phases formed by one‐dimensional coordination polymers [Co(bpy)₂(β‐Mo₈O₂₆)_0.5]_n (4) and [(MoO₃)(bpy)]_n (5). The crystal structures of 1–3 correspond to molecular salts self‐assembled by C—H…O—Mo, C…H and H…H intermolecular contacts. A Hirshfeld surface analysis for 1 showed that the C…H and H…H interactions represent an average of 51.8% of the total cation–cation intermolecular contacts. In contrast, these interactions are vastly reduced in 2 (23.0%) and 3 (average 28.5% for both isomers). EPR experiments indicated that the crystal structures of 1 and 3 are paramagnetic, and that for 2 is diamagnetic. The paramagnetism of 3 stems from the in situ formation of [Co(bpy)₃]³⁺ in a high‐spin configuration. The structure‐directing properties of the [Co(bpy)₃]ⁿ⁺ cations in the isolation and self‐assembly of concomitant octamolybdate isomers are also described from the viewpoint of crystal engineering.

中文翻译：

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使用均相CoII / CoIII复合物作为结构指导模板分离的亚稳晶体结构中的八钼酸盐异构体的伴随性

利用水热条件提供的动力学域，可以分离出三个瞬变的亚稳态晶体结构，每个结构都伴随着八对钼酸同分异构体对，即通过独特的均相稳定剂稳定的α–β，γ–β或_βcs –β _gp。联吡啶）₃ ] ^{ñ +}（BPY = 2,2'-联吡啶; ñ  = 2或3）的阳离子产生的原位：[CO（BPY）₃ ] ₄ [（α-沫₈ ø ₂₆）（β-沫₈ ö ₂₆）]·5H ₂ O（1），[NH ₄ ] [Co（bpy）₃ ] [（γ‐Mo ₈ø ₂₆）_0.5（β-沫₈ ö ₂₆）_0.5 ]·4H ₂ O（2）和[CO（BPY）₃ ] ₂ [（β _CS -Mo ₈ ö ₂₆）_0.5（β _GP -Mo ₈ ö ₂₆） ]·12H ₂ O（3）。固体1，空间群P 2 ₁ / Ñ和晶胞参数一个 = 22.160（6），b  = 14.209（3），C ^ = 24.641（4），β= 99.10（2）°，V  = 7661（3）埃³导致相同的晶体结构，通过太阳不同条件下预先合成等。[ J. Mol。结构。（2005年），741，149-153。通过分析在不同实验条件下获得的散装固体的PXRD图谱，可以监测指导反应的因素，例如产物组成和相稳定性。的混合相的相对比例1 - 3或它们的稳定化是高度依赖于初始钴：钼的摩尔比和反应温度。特别是温度升高会引起1 –3成一维的配位聚合物形成热力学更稳定相[CO（BPY）₂（β-沫₈ ö ₂₆）_0.5 ] _Ñ（4）和[（的MoO ₃）（联吡啶）] _Ñ（5）。的晶体结构1 - 3分别对应于分子的盐的自组装由C-H ... O-Mo系，C ... H和H ... H的分子间接触。对1的Hirshfeld表面分析表明，C…H和H…H相互作用平均代表总阳离子-阳离子分子间接触的51.8％。相比之下，这些互动减少了2（23.0％），3（两种异构体的平均值为28.5％）。EPR实验表明1和3的晶体结构是顺磁性的，而2的晶体结构是抗磁性的。3的顺磁性来自于[Co（bpy）₃ ] ³⁺在高自旋结构中的原位形成。从晶体工程的角度，还描述了[Co（bpy）₃ ] ^{n +}阳离子在伴生八钼酸盐异构体的分离和自组装中的结构导向特性。