INORGANIC CHEMISTRY COMMUNICATIONS
·
2016
·
IF 1.762
Wenping Wang,Bibi Ji,Chen Zhang,Xiaohua Cao
Firstly, we synthesized a novel spin crossover coordination compound 1 {[Fe(MPEG-trz) 3 ](BF 4 ) 2 }(MPEG-trz: polymeric ligand obtained by amidation reaction between methoxy polyethylene glycol (MPEG) and 4-amino-1,2,4-triazole (NH 2 -trz)). And then a suite of coordination compounds {[Fe(MPEG-trz) m (NH2-trz) n ](BF 4 ) 2 }(m = 2, n = 1, 2 ; m = 1.5, n = 1.5, 3 ; m = 1, n = 2, 4 ;) have been successively synthesized by self-assembly reaction between Fe(BF 4 ) 2 ·6H 2 O and MPEG-trz/NH 2 -trz in different proportion respectively. The structure detail is obtained through FT-IR, XRD and 1 H NMR measurements, while spin crossover behavior of these coordination compounds are inspected by superconducting quantum interference device (SQUID) and DSC . The new polymeric composites not only show mechanical behavior particular the malleability but also exhibit an abrupt spin crossover behavior with a slender hysteresis loop. Simultaneously we speculated the probably cooperative formation mechanism of spin crossover system on the based of analysis upon the magnetic performance among these coordination compounds with different proportions in MPEG-trz and NH 2 -trz.
研究领域:
材料化学
·
配位化学
·
物理化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2021
·
IF 5.165
Zhi-Kun Liu,Zi-Shuo Yao,Jun Tao
Halogen-substituted Fe(III) compounds, [Fe(HphsalpmX)2]PTFB (HphsalpmX = 5-X-(R,S)-((phenyl(2-pyridyl)methylimino)methyl)phenol, PTFB = phenyltrifluoroborate; X = F for 1, Cl for 2, Br for 3) and [Fe(HphsalpmX)2]PTFB·MeOH (X = I for 4·MeOH), were synthesized. Compounds 1, 4·MeOH, and its desolvated form 4 exhibited an invariant high-spin state in the whole temperature range, while 2 and 3 underwent gradual, nonhysteretic, and incomplete spin crossover (SCO) with transition temperatures (TC) of 153 and 220 K, respectively. Interestingly, the SCO-active compounds 2 and 3 showed light-induced excited spin-state trapping (LIESST) effects at 10 K, and light-induced reversible ON/OFF switching behaviors were realized by alternately using 880 and 1064 nm light, while the thermally inert compound 4·MeOH unexpectedly showed a reverse-LIESST effect. These results may help to design and synthesize new photoresponsive SCO Fe(III) compounds for the development of switchable materials.
研究领域:
无机化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2019
·Vol. 125
·期 9
·1-6
·
IF 1.784
Zhao Tian,Dong Ming,Zhao Yi
[Fe(HB(pz) 3 ) 2 ], a well-studied spin-crossover (SCO) complex, has been entrapped in NH 2 -MIL-101(Al) metal–organic framework (MOF) via gas diffusion method. [Fe(HB(pz) 3 ) 2 ] would sublimate when temperature exceeds 100 °C, especially at low pressure. Thus, in the selected condition, [Fe(HB(pz) 3 ) 2 ] molecules can be sublimated to a gas phase and diffused into the pores of NH 2 -MIL-101(Al), which yield [Fe(HB(pz) 3 ) 2 ]@MIL-101 hybrid materials. The identity of composites, with a loading of iron complex at ~ 8 wt%, was characterized by X-ray diffraction and spectroscopic attestation. The hybrid materials demonstrate a gentle spin transition curve from 300 to 400 K, which is different from the SCO behavior of [Fe(HB(pz) 3 ) 2 ]. And for the pure [Fe(HB(pz) 3 ) 2 ] sample at 400 K, only 60% of Fe(II) is in HS, while in hybrid samples, HS state is complete. This interesting phenomenon might indicate that the spin transition in the hybrid sample can be triggered at lower temperature. The composite samples were thoroughly studied by X-ray diffraction, IR spectroscopy, atom absorption spectroscopy, nitrogen physisorption, and magnetic measurements. Thereby, a novel MOF-based material with isolated SCO units is proposed, which demonstrate a salient ‘matrix-effect’ on spin-crossover behavior of [Fe(HB(pz) 3 ) 2 ].
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2021
·Vol. 50
·期 32
·11106-11112
·
IF 4.39
Qi Zhao,Jin-Peng Xue,Zhi-Kun Liu,Zi-Shuo Yao,Jun Tao
A mononuclear complex with long alkyl chains, [FeII(H2Bpz2)2(C9bpy)] (1; H2Bpz2 = dihydrobis(1-pyrazolyl)borate, C9bpy = 4,4′-dinonyl-2,2′-bipyridine), was synthesized. Single-crystal X-ray crystallographic studies revealed that the Δ- and Λ-forms of the complex co-crystallized in the lattice asymmetric unit, while magnetic measurements unveiled that this complex underwent incomplete one-step spin crossover (SCO) with the transition completeness and temperature depending on the measurement velocity because of slow spin equilibrium. Multivariable approaches such as varying scan rate, annealing the sample, light irradiation and pressure have been adopted to effectively overcome the slow spin equilibrium and thus improve the SCO completeness.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 10
·2363
·
IF 5
Di Wang,Ren Zhang,Jin Liu,Bibi Ji,Wenping Wang,Mengyuan Peng,Chen Huang,Lizhuoran Cheng,Yi Ding
A novel one-dimensional malleable spin-crossover (SCO) complex {[Fe(MPEG-trz)3](BF4)2} has been successfully synthesized by molecular self-assembly between 4-amino-1,2,4-triazoles (MPEG-trz) grafted with a long flexible chain methoxy polyethylene glycol (MPEG) and metallic complex Fe(BF4)2•6H2O. The detailed structure information was illustrated by using FT-IR and1H NMR measurements, while the physical behaviors of the malleable SCO complexes were systematically investigated by using magnetic susceptibility measurements using superconductivity quantum interference device (SQUID) and differential scanning calorimetry (DSC). This new metallopolymer exhibits a remarkable spin crossover transition behavior, between two spin quantum states (Fe2+ions): high spin (HS) state (quintet state) and low spin (LS) state (singlet state), at a specific critical temperature with a slender hysteresis loop of 1 K. DFT computations revealed the partial rules of HOMO-LUMO energy levels and spin density distributions of different four-position substituted [Fe(1,2,4-triazole)3]2+derivatives with different length of repeat units in polymer complexes. This can go a step further to depict the spin and magnetic transition behaviors of SCO polymer complexes. Furthermore, the coordination polymers possess an excellent processability due to an outstanding malleability, which can be easily shaped into a polymer film with spin magnetic switching properties.Keywords:spin crossover (SCO) complex;malleable;magnetic transition polymer;modification;MPEG films
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 13
·3251-3258
·
IF 7.779
Chun-Feng Wang,Jin Chuan Wu,Qingxin Li
A new spin crossover-fluorescent compound whose magnetic and fluorescence properties can be simultaneously controlled by multiple external stimuli was prepared. This compound possesses a 2D Hoffman-type structure and its spin crossover transition usually demonstrates high sensitivity toward intriguing effects such as the change of solvent guests. Due to the strong correlations between the spin state and fluorescence emission, the magnetic and fluorescence properties of this material can be synchronously tuned by not only physical thermal treatment, but also the chemical stimuli of solvent guests. Upon desorption or adsorption of the solvent guests, both the temperature-dependent magnetic susceptibility and fluorescence intensity can be reversibly varied between three-, one-, and two-stepped transitions, accompanied by wide thermal hysteresis loops. The synchronous control of magnetic and fluorescence behaviors through multiple external stimuli may give a new perspective to developing novel multifunctional materials.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2021
·Vol. 2021
·期 38
·3992-3999
·
IF 2.524
Bing-Xue Luo,Yao Pan,Yin-Shan Meng,Qiang Liu,Jun Yin,Tao Liu,Yuan-Yuan Zhu
Graphical A magneto-fluorescent bifunctional Fe(II) complex is synthesized through decoration of the pyrene fluorophore to Fe(II)-pybox moiety. Its magnetic and fluorescent properties are characterized via X-ray structural analyses, magnetic susceptibility measurement, 57 Fe Mössbauer spectroscopy, and fluorescent spectroscopy. As expected, the coexistence of spin-crossover and fluorescence is achieved. The construction of magneto-fluorescent bifunctional complexes is a feasible approach toward multifunctional molecular materials. Herein we report the synthesis and properties studies of a mononuclear Fe(II) complex [Fe L 2 ](ClO 4 ) ( 1 ), where L is a pyridine-2,6-bis(oxazoline) (pybox) ligand decorated by the pyrene fluorophore. Magnetic susceptibility measurement of desolvated complex 1-d shows an incomplete and gradual spin-crossover in the temperature range 50–300 K, which is further confirmed via 57 Fe Mössbauer spectroscopy study. Light-induced excited spin state trapping (LIESST) is also observed below 70 K when the powder sample is irradiated by a 532 nm laser. The change in absorption during the spin-crossover (SCO) process is investigated via the temperature-dependent UV-vis spectroscopy. As expected, through introducing the chromophore, 1 displays fluorescence in both solution and solid state, achieving the coexistence of spin-crossover and fluorescence in one compound.
研究领域:
无机化学
·
分子材料科学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Chun-Feng Wang,Zi-Shuo Yao,Guo-Yu Yang,Jun Tao
Six analogue compounds with the general formula [Fe2(xL)5(NCS)4]·yMeOH (x = o-Cl, y = 3 for compound 1; x = m-Cl, y = 5 for 2; x = p-Cl, y = 1 for 3; x = o-Me, y = 2 for 4; x = m-Me, y = 2 for 5; x = p-Me, y = 3 for 6; L = N-phenylmethylene-4-amino-1,2,4-triazole) were synthesized. The two Fe(II) ions are triply bridged by the triazole groups of three xL ligands and each Fe(II) is further capped with two NCS– groups and one more xL ligand. These compounds show regular patterns in their magnetic properties that depend on the positions the substituent groups (−Cl or −Me) ride, i.e., ortho-substituted compounds 1 and 4 undergo complete one-step spin crossover (SCO), while meta-substituted compounds 2 and 5 display incomplete one-step SCO with lower transition temperatures, and para-substituted compounds 3 and 6 are in the high-spin states in all temperature ranges. Structural analyses reveal that the molecular geometry and intermolecular interactions of these compounds, which should account for the differences in magnetic properties, are obviously depend on the positions of substituent groups (steric effect), despite them being electron-withdrawing chlorine or electron-donating methyl, whereas theoretical calculations confirm that the electronic effects of substituent groups exert no effect on the magnetic properties.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）