摘要 : The mixed N_3S(thiolate)ligand 1-[bis{2-(pyridin-2-yl)ethyl}ami-no]-2-methylpropane-2-thiol(Py_2SH)was used in the synthesis of four iron(II)complexes:[(Py_2S)FeCl](1),[(Py_2S)FeBr](2),[(Py_2S)_4Fe_5~(II)(mu-OH)_2]-(BF_4)_4(3),and... 展开 The mixed N_3S(thiolate)ligand 1-[bis{2-(pyridin-2-yl)ethyl}ami-no]-2-methylpropane-2-thiol(Py_2SH)was used in the synthesis of four iron(II)complexes:[(Py_2S)FeCl](1),[(Py_2S)FeBr](2),[(Py_2S)_4Fe_5~(II)(mu-OH)_2]-(BF_4)_4(3),and [(Py_2S)_2Fe_2~(II)(mu-OH)]BF_4(4).The X-ray structures of 1 and 2 revealed monomeric iron(II)-alkylthiolate complexes with distorted trigonal-bi-pyramidal geometries.The paramagnetic ~1H NMR spectra of 1 and 2 display resonances from delta =-25 ppm to + 100ppm,consistent with a high-spin iron(II)ion(5 = 2).Spectral assignments were made on the basis of chemical shift information and T_1 measurements and show the monomeric structures are intact in solution.To provide entry into hydroxide-containing complexes,a novel synthetic method was developed involving strict aprotic conditions and limiting amounts of H_2O.Reaction of Py_2SH with NaH and Fe-(BF_4)_2 centre dot 6H_2O under aprotic conditions led to the isolation of the pentanuclear,mu-OH complex 3,which has a novel dimer-of-dimers type structure connected by a central iron atom.Conductivity data on 3 show this structure is retained in CH_2Cl_2.Rational modification of the ligand-to-metal ratio allows control over the nuclearity of the product,yielding the dinuclear complex 4.The X-ray structure of 4 reveals an unprecedented face-sharing,biooctahe-dral complex with an [S_2O] bridging arrangement.The magnetic properties of 3 and 4 in the range 1.9-300 K were successfully modeled.Dinuclear 4 is antiferromagnetically coupled [J= - 18.8(2)cm~(-1)].Pentanuclear 3 exhibits ferrimagnetic behavior,with a high-spin ground state of S_T=6,and was best modeled with three different exchange parameters [J=-15.3(2),J' =-24.7(3),and J" =-5.36(7)cm~(-1)].DFT calculations provided good support for the interpretation of the magnetic properties. 收起