SYNTHESIS, MOLECULAR-STRUCTURE, AND SOLUTION PROPERTIES OF A PHENOLATE-BRIDGED (TETRAARYLPORPHINATO)IRON(III) DIMER
SYNTHESIS, MOLECULAR-STRUCTURE, AND SOLUTION PROPERTIES OF A PHENOLATE-BRIDGED (TETRAARYLPORPHINATO)IRON(III) DIMER
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DOI：
10.1021/ic00171a009
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发表时间：
1984-01-01
影响因子：
4.6
通讯作者：
SCHEIDT, WR
中科院分区：
文献类型：
--
作者：
GOFF, HM;SHIMOMURA, ET;SCHEIDT, WR
Á 与非卟啉铁 (III) 酚盐络合物观察到的结果相当。质子 NMR 谱揭示了高自旋铁 (III) 中心诊断的 80 ppm 区域中的吡咯信号。在远下场和远上场区域也观察到配位酚盐基团的信号。还原成铁 (II) 态会导致酚盐桥断裂，质子 NMR 谱与方形平面 S= 1（卟啉）铁 (II) 单体的形成一致。该物质在水饱和的甲苯中的空气氧化用于再生二聚酚盐络合物。二聚体 ((TTOP) Fe) 2 表现出与高自旋铁 (III) 的仅自旋值相匹配的溶液和固态磁矩。因此金属中心之间的反铁磁耦合非常小。由于仅相隔 6 的金属中心之间存在有效的自旋-自旋电子弛豫，因此在 77 K 时没有观察到 EPR 光谱。 2 A。电化学测量揭示了两个可逆的还原波和复杂的重叠氧化波。二聚酚盐络合物具有适合多电子氧化还原催化剂的性质。
Á is comparable to that observed for non-porphyrin iron (III) phenolate complexes. Proton NMR spectra reveal pyrrole signals in the 80 ppm region diagnostic of a high-spin iron (III) center. Signals for the coordinatedphenoxide groups are also observed in far-downfield and far-upfield regions. Reduction to the iron (II) state brings cleavage of phenoxide bridges, and proton NMR spectra are consistent with formation of a square-planar S= 1 (porphinato) iron (II) monomer. Air oxidation of this species in water-saturated toluene serves to regenerate the dimeric phenolate complex. The dimeric ((TTOP) Fe) 2 exhibits solution and solid-state magnetic moments that match the spin-only value for high-spin iron (III). Antiferromagnetic coupling between metal centers is thus very small. No EPR spectrum was observed at 77 K as a consequence of efficient spin-spin electronic relaxation between metal centers separated by only6. 2 Á. Electrochemicalmeasurements reveal two reversible reduction waves and complex overlapping oxidation waves. The dimeric phenolate complex has propertiesappropriate for a multielectron-redox catalyst.