The connections between different physical-chemical properties in homologous molecular series are analyzed from the quantum-mechanic and the algebraic theory points of view and are explained by influence of the gage t...The connections between different physical-chemical properties in homologous molecular series are analyzed from the quantum-mechanic and the algebraic theory points of view and are explained by influence of the gage to the quantum electronic continuum. The connection between quantum and macroscopic properties of the substances is confirmed in homologous series of n-alkanes. Linear correlation between the coefficient of magnetization and energy of the highest occupied molecular orbital in homologous series of n-alkanes C2-C10 is established. The connection between diamagnetic and electronic characteristics of n-alkanes with the temperatures of the first order phase transitions （melting point） and other physical-chemical properties were discovered. The nature of interconnection between critical and diamagnetic properties of n-alkanes C2-C10 and results of previous works allow to suppose significant role of the spin interactions in electronic continuum states along the process of the first order phase transitions.展开更多
Many sandwich-type lanthanide complexes show extremely high energy barriers(Ueff)for the reversal of magnetization and high blocking temperatures,being the star molecules in the research area of single-molecule magnet...Many sandwich-type lanthanide complexes show extremely high energy barriers(Ueff)for the reversal of magnetization and high blocking temperatures,being the star molecules in the research area of single-molecule magnets.Herein,the preparation,structural determination,and magnetic property studies of two ansa-bridged Er-COT(COT=cyclooctatetraenyl dianion)complexes[KDME_(2)][Er((η^(8)-COT-Si^(Me2))_(2)O)](1)and[KDME_(2)][Er((η^(8)-COT-Si^(iPr2))_(2)O)]K[Er((η^(8)-COT-Si^(iPr2))_(2)O)](2)were reported.The Er(Ⅲ)ions in both complexes are sandwiched by two COT rings which are ansa-bridged by a[Si-O-Si]group.Magnetic studies reveal both complexes display slow magnetic relaxations with comparable energy barriers(228(5)K for 1,and 196(4)K for 2)and blocking temperatures(10.5 K for both complexes).The difference in the relaxation times(τ)for the two complexes was studied in details:different molecular vibrations induced by the substituents are the main reason forτfor 1 being about 10 times longer than for 2 at the same temperature above 10 K,while the quantum tunnelling of magnetization relaxation time(τQTM)for 2 is about 10 times longer than for 1 below 8 K,probably owing to the different dipolar interactions.Further rearrangement of molecular network with such ansa-bridged SMMs is promising to design molecular magnetic materials with enhanced properties or new properties.展开更多
文摘The connections between different physical-chemical properties in homologous molecular series are analyzed from the quantum-mechanic and the algebraic theory points of view and are explained by influence of the gage to the quantum electronic continuum. The connection between quantum and macroscopic properties of the substances is confirmed in homologous series of n-alkanes. Linear correlation between the coefficient of magnetization and energy of the highest occupied molecular orbital in homologous series of n-alkanes C2-C10 is established. The connection between diamagnetic and electronic characteristics of n-alkanes with the temperatures of the first order phase transitions （melting point） and other physical-chemical properties were discovered. The nature of interconnection between critical and diamagnetic properties of n-alkanes C2-C10 and results of previous works allow to suppose significant role of the spin interactions in electronic continuum states along the process of the first order phase transitions.
基金supported by the National Natural Science Foundation of China(92261203,22101116,and 21971106)Key Laboratory of Rare Earth Chemistry of Guangdong Higher Education Institutes(2022KSYS006)+1 种基金the Stable Support Plan Program of Shenzhen Natural Science Fund(20200925161141006)Shenzhen Fundamental Research Program(JCYJ20220530115001002 and JCYJ20220818100417037).
文摘Many sandwich-type lanthanide complexes show extremely high energy barriers(Ueff)for the reversal of magnetization and high blocking temperatures,being the star molecules in the research area of single-molecule magnets.Herein,the preparation,structural determination,and magnetic property studies of two ansa-bridged Er-COT(COT=cyclooctatetraenyl dianion)complexes[KDME_(2)][Er((η^(8)-COT-Si^(Me2))_(2)O)](1)and[KDME_(2)][Er((η^(8)-COT-Si^(iPr2))_(2)O)]K[Er((η^(8)-COT-Si^(iPr2))_(2)O)](2)were reported.The Er(Ⅲ)ions in both complexes are sandwiched by two COT rings which are ansa-bridged by a[Si-O-Si]group.Magnetic studies reveal both complexes display slow magnetic relaxations with comparable energy barriers(228(5)K for 1,and 196(4)K for 2)and blocking temperatures(10.5 K for both complexes).The difference in the relaxation times(τ)for the two complexes was studied in details:different molecular vibrations induced by the substituents are the main reason forτfor 1 being about 10 times longer than for 2 at the same temperature above 10 K,while the quantum tunnelling of magnetization relaxation time(τQTM)for 2 is about 10 times longer than for 1 below 8 K,probably owing to the different dipolar interactions.Further rearrangement of molecular network with such ansa-bridged SMMs is promising to design molecular magnetic materials with enhanced properties or new properties.
