Redox-Active Metallodithiolene Groups Separated by Insulating Tetraphosphinobenzene Spacers
Redox-Active Metallodithiolene Groups Separated by Insulating Tetraphosphinobenzene Spacers
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DOI：
10.1021/acs.inorgchem.8b00201
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发表时间：
2018-04-02
影响因子：
4.6
通讯作者：
Donahue, James P.
中科院分区：
文献类型：
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作者：
Arumugam, Kuppuswamy;Selvachandran, Malathy;Donahue, James P.
[（S2 C2 R2）M（mu-tpbz）M-（S2 C2 R2）]型化合物（R = CN、Me、Ph、对茴香基; M = Ni、Pd、Pt; tpbz = 1，2，4，5-四氢萘（二苯基膦基）苯）已通过与[（S2 C2 R2）SnR '（2）]试剂的金属转移反应，通过用0.5当量的tpbz直接置换[M（S2 C2 R2）（2）]中的二硫杂环戊烯配体来制备，或通过使用Na-2[S2 C2（CN）（2）]结合X2 M（mu-tpbz）MX2（X =卤化物）的盐复分解。X射线晶体学揭示了（S2 C2）M（P2 C6 P2）M（S2 C2）核的一系列拓扑结构（波状，椅状，弓形）。[（S2 C2 R2）M（mu-tpbz）M（S2 C2 R2）]（R = Me、Ph、p-茴香基）化合物支持可逆或准可逆氧化，其对应于二硫杂环戊烯末端配体从烯-1，2-二硫代酸盐到自由基单阴离子的同时氧化，形成[（（-SSC 2 R2）-S-中心点）M（mu-tpbz）M（（-SSC 2 R2）-S-中心点）]（2+）。R= Ph和对茴香基化合物支持二硫杂环戊烯配体第二次可逆氧化成它们的α-二硫杂环戊烯形式。相反，[（S2 C2（CN）（2））Ni（tpbz）Ni（S2 C2（CN）（2））]仅维持可逆的金属中心还原。通过EPR对R[（（-SSC 2）-S-中心点（对茴香基）（2））Ni（mu-tpbz）Ni（（-SSC 2）-S-中心点（对茴香基）（2）]（2+）进行光谱检查，揭示了近简并的单重态-三重态基态，光谱模拟揭示了非常小的偶极耦合常数18 x 10（-4）cm（-1），代表11.3埃的自旋间距离。这种弱相互作用是由刚性的tpbz配体介导的，其电子绝缘的能力是发展分子基自旋电子器件的基本品质。
Compounds of the type [(S2C2R2)M(mu-tpbz)M-(S2C2R2)] (R = CN, Me, Ph, p-anisyl; M = Ni, Pd, Pt; tpbz = 1,2,4,5-tetralds(diphenylphosphino)benzene) have been prepared by transmetalation with [(S2C2R2)SnR'(2)] reagents, by direct displacement of dithiolene ligand from [M(S2C2R2)(2)] with 0.5 equiv of tpbz, or by salt metathesis using Na-2[S2C2(CN)(2)] in conjunction with X2M(mu-tpbz)MX2 (X = halide). X-ray crystallography reveals a range of topologies (undulating, chair, bowed) for the (S2C2)M(P2C6P2)M(S2C2) core. The [(S2C2R2)M(mu-tpbz)M(S2C2R2)] (R = Me, Ph, p-anisyl) compounds support reversible or quasireversible oxidations corresponding to concurrent oxidation of the dithiolene terminal ligands from ene-1,2-dithiolates to radical monoanions, forming [((-SSC2R2)-S-center dot)M(mu-tpbz)M((-SSC2R2)-S-center dot)](2+). The R= Ph and p-anisyl compounds support a second, reversible oxidation of the dithiolene ligands to their a-dithione form. In contrast, [(S2C2(CN)(2))Ni(tpbz)Ni(S2C2(CN)(2))] sustains only reversible, metal-centered reductions. Spectroscopic examination of R[((-SSC2)-S-center dot(p-anisyl)(2))Ni(mu-tpbz)Ni((-SSC2)-S-center dot(p-anisyl)(2))](2+) by EPR reveals a near degenerate singlet-triplet ground state, with spectral simulation revealing a remarkably small dipolar coupling constant of 18 x 10(-4) cm(-1) that is representative of an interspin distance of 11.3 angstrom. This weak interaction is mediated by the rigid tpbz ligand, whose capacity to electronically insulate is an essential quality in the development of molecular-based spintronic devices.