A smart post-synthetic route towards[Fe_(2)Co_(2)]molecular capsules with electron transfer and bidirectional switching behaviors

Aldehyde groups were intentionally equipped on the cyanide-bridged[Fe_(2)Co_(2)]square molecules:{[(Tp*)Fe(CN)_(3)Co(bpy^(CHO))_(2)]_(2)-[PF_(6)]_(2)}·4MeOH(1,Tp*=hydrotris(3,5-dimethylpyrazol-1-yl)borate;bpy^(CHO)=4-formyl-4′-methyl-2,2′-bipyridine),thus providing chemical-active windows for post-modification towards desired functions.In this contribution,by taking advantage of efficient Schiff-base condensation between the aldehyde-substituted bipyridine derivative(bpyCHO)and alkyl diamines(H_(2)N-(CH_(2))_(n)NH_(2)),two discrete[Fe_(2)Co_(2)]compounds{[(Tp∗)Fe(CN)_(3)Co(bpy^(C=N(CH_(2))_(n)N=C)bpy)]2[PF_(6)]_(2)}⋅6DMF(2,n=5;3,n=7)were prepared,where the cyanide-bridged[Fe_(2)Co_(2)]square cores were encapsulated by the flexible alkyl chains.Variable-temperature single-crystal X-ray diffraction and magnetic studies revealed complete thermo(T_(1/2)=233 K(2)and 237 K(3))and photo-induced electron transfer event accompanying spin transition between the diamagnetic[Fe^(Ⅱ)_(LS2)Co^(Ⅲ)_(LS2)]state and the paramagnetic[Fe^(Ⅲ)_(LS2)Co^(Ⅱ)_(HS2)]state(LS,low spin;HS,high spin).In addition,the bidirectional switching between the two states was achieved with alternating laser irradiation at 808 and 532 nm at 10 K.

Decode-and-Forward Relay Based Bidirectional Wireless Information and Power Transfer

In this paper, we propose the decode-and-forward(DF) based bidirectional wireless information and power transfer(BWIPT) in two-hop relay systems, where the bidirectional relay can decode and forward information from the user to the access point(AP), and assist the wireless power transfer from the AP to the user. To maximize the information rate from the user to the AP, we derive the closed form expression of the optimal power splitting(PS) factor, and the time allocation scheme to obtain the optimal time switching(TS) factor. Simulation results show that for both PS and TS protocols, the proposed DF based bidirectional relay systems can improve the information rate as compared with the amplify-and-forward(AF) based bidirectional relay systems.

Multi-Phase QR ZCS Switched-Capacitor Bidirectional Power Converter for PV System Application

The multi-phase implementation in the QR （quasi resonant） ZCS （zero current switching） SC （switched capacitor） bidirectional DC-DC converter structure has been proposed to reduce current ripple, switching loss and significantly increase the converter efficiency and power density. This approach provides a more precise output voltage to obtain voltage conversion ratios from the double-mode versus half-mode to n-mode versus 1/n mode. This is accomplished by adding a different number of switched-capacitors and power MOSFET switches with a small series connected resonant inductor for forward and reverse schemes. The size and cost can be reduced when the proposed converter has been designed with the coupled inductors. The simulation and experimental results have been used to demonstrate the performance of the two-phase with and without coupled inductor interleaved QR ZCS SC converters for bidirectional power flow control application, and an extending structure for N-phase is mentioned.

Ligand Modified and Light Switched On/Off Single-Chain Magnets of {Fe_(2)Co} Coordination Polymers via Metal-to-Metal Charge Transfer

It is still a formidable challenge to simultaneously switch single-chain magnet(SCM)behavior via ligand modification and light irradiation in the field of molecular spintronics.Herein,we present a ligandbridged layer{[pzTpFe(CN)3]4Co2(Bib)4}·3H2O(1;pzTp,tetra-kis(1-pyrazolyl)borate;Bib,1,4-bis-(1Himidazol-1-yl)benzene)and a well-isolated double chain{[pzTpFe(CN)3]2Co(Bpi)2}·CH3CN·4H2O(2;Bpi,1-Biphenyl-4-yl-1H-imidazole)that display reversible metal-to-metal charge transfer(MMCT)between FeIII LS(μ-CN)CoII HS(μ-NC)FeIII LS(LS,low spin;HS,high spin)and FeIII LS(μ-CN)CoIII LS(μ-NC)FeII LS linkages under alternating irradiation with 808 and 532 nm lasers.The bidirectional light irradiations induces significant changes in anisotropy and intrachain magnetic interactions,resulting in the on/off switching of SCM behavior with observable hysteresis loops by 808 and 532 nm light irradiations for both compounds.Because of the ligand modification,the SCM property of 2 with the monodentate ligand is greatly improved with a correlation length increased to 83,which is the largest correlation length among all reported light actuated SCMs.Furthermore,the influence of ligand modification on their thermally induced MMCT is also discussed.This study provides a rational approach for the swift and reversible control of SCM behavior via ligand modified and light induced MMCT,which is crucial to the future technological demand for high-density data storage and processing.