The first air-stable Ln(III)organometallic mixed-ligand sandwich complexes TPPLnCp^(*)(Ln=Y(1),Tb(2),Dy(3),Ho(4),and Er(5))bearing both 5,10,15,20-tetraphenylporphyrinate(TPP)and pentamethylcyclopentadienide(Cp^(*))li...The first air-stable Ln(III)organometallic mixed-ligand sandwich complexes TPPLnCp^(*)(Ln=Y(1),Tb(2),Dy(3),Ho(4),and Er(5))bearing both 5,10,15,20-tetraphenylporphyrinate(TPP)and pentamethylcyclopentadienide(Cp^(*))ligands were synthesized by the reactions of half-sandwich bis(o-N,N-dimethylaminobenzyl)precursors Cp^(*)Ln(CH_(2)C_(6)H_(4)NMe_(2-o))_(2)with equimolar amounts of 5,10,15,20-tetraphenylporphyrin(TPPH2)in toluene at ambient temperature and isolated in 62%–74%yields.X-ray analysis revealed the linear Cnt(Cp^(*))–Ln–Cnt(TPP)geometry with a bond angle close to 180°,a Cnt(Cp^(*))–Ln bond distance ranging from 2.325 to 2.365Åand a Cnt(TPP)–Ln distance ranging from 1.012 to 1.063Å.These complexes demonstrated remarkable thermal and oxidative stability,being sublimable under vacuum above 290°C without decomposition(∼5×10^(−2)Torr).Magnetic studies revealed field-induced single-molecule magnet(SMM)behavior for the Tb^(3+),Dy^(3+),and Er^(3+)derivatives.Theoretical investigations revealed the presence of only moderately axial g tensors,a small splitting within the ground multiplet,and significant mixing between different projections of the total angular momentum,all of which contribute to the disappointing SMM behavior.A quasi-spherical Ln^(3+)coordination environment created by the tetradentate TPP ligand and appreciable orbital interactions of itsπ-conjugated system with the dysprosium 4f orbitals could introduce transverse components to the crystal field.展开更多
基金support of the Russian Science Foundation is highly acknowledged(Project No.24-13-00275)support from the Ministry of Science and Higher Education of the Russian Federation(Contract No.075-00277-24-00).
文摘The first air-stable Ln(III)organometallic mixed-ligand sandwich complexes TPPLnCp^(*)(Ln=Y(1),Tb(2),Dy(3),Ho(4),and Er(5))bearing both 5,10,15,20-tetraphenylporphyrinate(TPP)and pentamethylcyclopentadienide(Cp^(*))ligands were synthesized by the reactions of half-sandwich bis(o-N,N-dimethylaminobenzyl)precursors Cp^(*)Ln(CH_(2)C_(6)H_(4)NMe_(2-o))_(2)with equimolar amounts of 5,10,15,20-tetraphenylporphyrin(TPPH2)in toluene at ambient temperature and isolated in 62%–74%yields.X-ray analysis revealed the linear Cnt(Cp^(*))–Ln–Cnt(TPP)geometry with a bond angle close to 180°,a Cnt(Cp^(*))–Ln bond distance ranging from 2.325 to 2.365Åand a Cnt(TPP)–Ln distance ranging from 1.012 to 1.063Å.These complexes demonstrated remarkable thermal and oxidative stability,being sublimable under vacuum above 290°C without decomposition(∼5×10^(−2)Torr).Magnetic studies revealed field-induced single-molecule magnet(SMM)behavior for the Tb^(3+),Dy^(3+),and Er^(3+)derivatives.Theoretical investigations revealed the presence of only moderately axial g tensors,a small splitting within the ground multiplet,and significant mixing between different projections of the total angular momentum,all of which contribute to the disappointing SMM behavior.A quasi-spherical Ln^(3+)coordination environment created by the tetradentate TPP ligand and appreciable orbital interactions of itsπ-conjugated system with the dysprosium 4f orbitals could introduce transverse components to the crystal field.
