Group 10 Metal Dithiolene Bis(isonitrile) Complexes: Synthesis, Structures, Properties, and Reactivity
Group 10 Metal Dithiolene Bis(isonitrile) Complexes: Synthesis, Structures, Properties, and Reactivity
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DOI：
10.1021/acs.organomet.0c00375
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发表时间：
2020-08-10
期刊：
影响因子：
2.8
通讯作者：
Donahue, James P.
中科院分区：
文献类型：
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作者：
Obanda, Antony;Valerius, Kendra;Donahue, James P.
[（Ph 2C 2S 2）（2）M]的反应（M = Ni 2+、Pd 2+、Pt 2+）与2当量的RNC（R = Me（a），Bn（B），Cy（c），Bu-t（d），1-Ad（e），Ph（f））产生[（Ph2C2S2）M（CNR）（2）]（M = Ni 2+，4a-f; M = Pd 2+，5a-f; M = Pt 2+，6a-f），它们是空气稳定的并且适合于色谱纯化。所有成员都进行了晶体学表征。在结构上，逐渐更大的平面性倾向于表现为M从Ni到Pt的变化，并且协调的C NR的C N键长的适度减少出现在从Ni向Pt移动中。振动光谱（CH 2Cl 2溶液）揭示了[（Ph 2C 2S 2）M（C NR）（2）]的nu（C N）频率显著高于游离C NR的频率，并且随着M范围从Ni到Pt而增加。这种趋势被解释为产生于M处的正电荷增加，其使配体的线性、电荷分离共振形式稳定于具有降低的C-N键级的弯曲形式。紫外-可见光谱揭示了最低能量跃迁，其被指定为HOMO（二硫杂环戊烯π）-> LUMO（M-L σ *）激发。[（Ph_2C_2S_2）M（CNR）（2）]的单电子氧化反应在+0.5V附近进行，其原因是Ph_2C_2S_22->（Ph_2C_2S-S中心点）+ e（-）。[（Ph2C2S2）Pt（C（NBu）-Bu-t）（2）]与[（Br-p-C6 H4）（3）N][SbCl 6]产生[（（Ph 2C 2S-S中心点））Pt（C（NBu）-Bu-t）（2）]（+），通过光谱鉴定，但处于结晶状态[[（（Ph_2C_2S-S中心点））Pt（C（NBu）-Bu-t）（2）]（2）]（2+）占优势，它通过轴向Pt中心点S相互作用和在金属上的结晶形成。在强制条件下用2，6-Me（2）py从[（Ph 2C 2S 2）Ni（C NMe）（2）]完全取代MeNC产生[（2，6-Me（2）py）Ni（mu（2）-eta（1），eta（1）-S '，eta（1）-S“”-S2 C2 Ph 2）]（2）（8），其特征在于折叠的Ni 2S 2核。在大多数情况下，用单齿配体（L =膦、CN-、卡宾）从[（Ph 2C 2S 2）M（C NMe）（2）]进行异氰化物取代得到[（Ph 2C 2S 2）M（L）（C NMe）]（n）（n = 0，1-），其中nu（C N）根据L（9-21）的相对供s能力而变化。使用1，3-双（2，6-二异丙基苯基）咪唑-2-亚基（IPr）可得到[（Ph 2C 2S 2）M（IPr）（C NMe）]，其中M = Ni（18），Pd（19），但对于Pt，IPr攻击异氰化物碳，产生不寻常的eta（1），kappa C-烯酮亚胺络合物[（Ph 2C 2S 2）Pt（C（NMe）（IPr））（C NMe）]（20）。
The reaction of [(Ph2C2S2)(2)M] (M = Ni2+, Pd2+, Pt2+) with 2 equiv of RN C (R = Me (a), Bn (b), Cy (c), Bu-t (d), 1-Ad (e), Ph (f)) yields [(Ph2C2S2)M(C NR)(2)] (M = Ni2+, 4a-f; M = Pd2+, 5a-f; M = Pt2+, 6a-f), which are air-stable and amenable to chromatographic purification. All members have been characterized crystallographically. Structurally, progressively greater planarity tends to be manifested as M varies from Ni to Pt, and a modest decrease in the C N bond length of coordinated C NR appears in moving from Ni toward Pt. Vibrational spectroscopy (CH2Cl2 solution) reveals nu(C N) frequencies for [(Ph2C2S2)M(C NR)(2)] that are substantially higher than those for free C NR and increase as M ranges from Ni to Pt. This trend is interpreted as arising from an increasingly positive charge at M that stabilizes the linear, charge-separated resonance form of the ligand over the bent form with lowered C-N bond order. UV-vis spectra reveal lowest energy transitions that are assigned as HOMO (dithiolene pi) -> LUMO (M-L sigma*) excitations. One-electron oxidations of [(Ph2C2S2) M(C NR)(2)] are observed at similar to+0.5 V due to Ph2C2S22- -> (Ph2C2S-S center dot) + e(-). Chemical oxidation of [(Ph2C2S2)Pt(C (NBu)-Bu-t)(2)] with [(Br-p-C6H4)(3)N][SbCl6] yields [((Ph2C2S-S center dot)) Pt(C (NBu)-Bu-t)(2)](+), identified spectroscopically, but in the crystalline state [[((Ph2C2S-S center dot))Pt(C (NBu)-Bu-t)(2)](2)](2+) prevails, which forms via axial Pt center dot center dot center dot S interactions and pyramidalization at the metal. Complete substitution of MeNC from [(Ph2C2S2)Ni(C NMe)(2)] by 2,6-Me(2)py under forcing conditions yields [(2,6-Me(2)py)Ni(mu(2)-eta(1),eta(1)-S',eta(1)-S ''-S2C2Ph2)](2) (8), which features a folded Ni2S2 core. In most cases, isocyanide substitution from [(Ph2C2S2)M(C NMe)(2)] with monodentate ligands (L = phosphine, CN-, carbene) leads to [(Ph2C2S2)M(L)(C NMe)](n) (n = 0, 1-), wherein nu(C N) varies according to the relative s-donating power of L (9-21). The use of 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) provides [(Ph2C2S2)M(IPr)(C NMe)] for M = Ni (18), Pd (19), but for Pt, attack by IPr at the isocyanide carbon occurs to yield the unusual eta(1),kappa C-ketenimine complex [(Ph2C2S2)Pt(C(NMe)(IPr))(C NMe)] (20).