The Au and Ni monoanionic complexes of tert-butyl and diisopropyl substituted thiophenedithiolate ligands,[M(α-tb-tpdt)_(2)]and[M(α-dp-tpdt)_(2)],were synthesized and characterized namely by single crystal X-ray dif...The Au and Ni monoanionic complexes of tert-butyl and diisopropyl substituted thiophenedithiolate ligands,[M(α-tb-tpdt)_(2)]and[M(α-dp-tpdt)_(2)],were synthesized and characterized namely by single crystal X-ray diffraction and magnetic susceptibility measurements.These complexes,prepared in a first step as monoanionic species,are easier to oxidize than the related non-substituted thiophenedithiolates and could be obtained also as stable neutral species.As expected,the peripheral alkyl groups in the ligands also confer a high solubility to the complexes in common organic solvents.The neutral gold complex[Au(α-tb-tpdt)_(2)]presents a significant ligand asymmetry indicative of unpaired electron localization in one ligand at variance with[Au(α-dp-tpdt)_(2)]that is within experimental uncertainty fully symmetric illustrating the role of intermolecular interactions in the stabilization of SOMO⋯SOMO interactions.While in[Au(α-tb-tpdt)_(2)]a significant intermolecular interaction between paramagnetic molecules is possible leading to diamagnetic dimers of molecules,in[Au(α-dp-tpdt)_(2)]the bulkier substituents prevent the intermolecular interactions,leading to a regular stacking of molecules in symmetrical configuration.The regular stacks of paramagnetic[Au(α-dp-tpdt)2]units behave,at high temperatures,as antiferromagnetic chains undergoing an AFM transition at ca.25 K.展开更多
基金supported by FCT(Portugal)through contracts UID/Multi/04349/2013,PTDC/QEQ-SUP/1413/2012 and RECI/QEQ-QIN/0189/2012doctoral grants to J.T.C.(SFRH/BD/84628/2012)R.A.L.S.(SFRH/BD/86131/2012).
文摘The Au and Ni monoanionic complexes of tert-butyl and diisopropyl substituted thiophenedithiolate ligands,[M(α-tb-tpdt)_(2)]and[M(α-dp-tpdt)_(2)],were synthesized and characterized namely by single crystal X-ray diffraction and magnetic susceptibility measurements.These complexes,prepared in a first step as monoanionic species,are easier to oxidize than the related non-substituted thiophenedithiolates and could be obtained also as stable neutral species.As expected,the peripheral alkyl groups in the ligands also confer a high solubility to the complexes in common organic solvents.The neutral gold complex[Au(α-tb-tpdt)_(2)]presents a significant ligand asymmetry indicative of unpaired electron localization in one ligand at variance with[Au(α-dp-tpdt)_(2)]that is within experimental uncertainty fully symmetric illustrating the role of intermolecular interactions in the stabilization of SOMO⋯SOMO interactions.While in[Au(α-tb-tpdt)_(2)]a significant intermolecular interaction between paramagnetic molecules is possible leading to diamagnetic dimers of molecules,in[Au(α-dp-tpdt)_(2)]the bulkier substituents prevent the intermolecular interactions,leading to a regular stacking of molecules in symmetrical configuration.The regular stacks of paramagnetic[Au(α-dp-tpdt)2]units behave,at high temperatures,as antiferromagnetic chains undergoing an AFM transition at ca.25 K.
