Caneschi Andrea, Dei Andrea, Mussari Christopher P, Shultz David A, Sorace Lorenzo, Vostrikova Kira E
INSTM, UdR Firenze and Dipartimento di Chimica dell'Università, Via Maragliano 75, 50144 Florence, Italy.
Inorg Chem. 2002 Mar 11;41(5):1086-92. doi: 10.1021/ic0106322.
The tris-bidentate ligand 1,3,5-tris(5'-tert-butyl-3',4'-dihydroxyphenyl)benzene ((TBCat)(3)Ph) was synthesized. The reaction of this molecule in basic solution with two paramagnetic acceptors, i.e., a nickel(II)minus signtetraazamacrocyclic ligand complex (Ni(CTH)) (CTH = dl-5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane) and manganese(II)-hydrotris[3-(4'-cumenyl)-5-methylpyrazolyl]borate (Mn(Tp(Cum,Me))), yielded two complexes whose analytical formulas are consistent with those of trinuclear complexes. Spectroscopic and magnetic measurements suggest that these derivatives contain divalent metal ions coordinated to the tris(semiquinone) form of the ligand. Analysis of the magnetic data shows that the pi-connectivity of the ligand enforces ferromagnetic coupling between the three semiquinone units of the molecule, giving rise to complexes with S = 9/2 (M = Ni(II)) and S = 6 (M = Mn(II)) ground states. The coupling within the tris(semiquinone) unit is quite large (J = -26 cm(-1) for the nickel(II) derivative and J = -40 cm(-1) for the manganese(II) one, using the general exchange Hamiltonian H = sigma J(ij)S(i)S(j)), and it is of the same order of magnitude as that observed in an analogous series of bis(semiquinone) complexes that we recently reported.
合成了三齿配体1,3,5-三（5'-叔丁基-3',4'-二羟基苯基）苯（(TBCat)(3)Ph）。该分子在碱性溶液中与两种顺磁性受体，即镍（II）-四氮杂大环配体配合物（Ni(CTH)）（CTH = dl-5,7,7,12,14,14-六甲基-1,4,8,11-四氮杂环十四烷）和锰（II）-氢三[3-(4'-异丙苯基)-5-甲基吡唑基]硼酸盐（Mn(Tp(Cum,Me))）反应，得到了两种配合物，其分析式与三核配合物一致。光谱和磁性测量表明，这些衍生物含有与配体的三（半醌）形式配位的二价金属离子。磁性数据分析表明，配体的π连接性增强了分子中三个半醌单元之间的铁磁耦合，产生了基态为S = 9/2（M = Ni(II)）和S = 6（M = Mn(II)）的配合物。三（半醌）单元内的耦合相当大（镍（II）衍生物J = -26 cm(-1)；锰（II）衍生物J = -40 cm(-1)，采用一般交换哈密顿量H = sigma J(ij)S(i)S(j)）），其量级与我们最近报道的一系列类似双（半醌）配合物中观察到的量级相同。
