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Photoswitchable room temperature phosphorescence (RTP) materials are of great interest due to their potential applications in optical devices and switches. Herein, two Zn‐based coordination polymers (CPs) (H3‐TPB)·[Zn6(H‐HEDP)(HEDP)3(H2O)2]·5H2O (complex 1; HEDP = hydroxyethylidene diphosphonate; TPB = 1,3,5‐tris(4‐pyridyl)benzene) and (H‐TPB)·[Zn3(H‐HEDP)(HEDP)(H2O)]·2H2O (complex 2) with distinguishable photochromism and tunable RTP are synthesized involving photoactive TPB molecules with different packing modes. Complex 1 exhibits bidirectionally on/off RTP regulation via on‐switch with excitation of 250−330 nm light and off‐switch with 350−380 nm, and the "turn‐on" behavior can be attributed to the advance of Förster resonance energy transfer‐assisted intersystem crossing (ISC) process while "turn‐off" process due to the transformation from H3‐TPB cations to H3‐TPB· radicals. Complex 2 exhibits photoswitchable RTP accompanied with reversible photochromism by leveraging the self‐absorption and RTP emission. Two demos based on the above compounds are further applied to demonstrate the application in information recording and encryption fields. This work supplies a strategy toward the design of switchable RTP systems using electron transfer photochromism, shedding light on broadening the frontiers of photoresponsive materials. [ABSTRACT FROM AUTHOR]

As promising photoresponsive materials and potential smart materials, hybrid photochromic materials (HPMs), especially for crystalline HPMs (CHPMs), have been broadly explored for their potential in inheriting the merits of each constituents, and intriguing photomodulated functionality. Hitherto, the photoresponsive functionality in explored CHPMs mainly concentrate on dyad combination. By contrast, triple or quadruple photoresponsive properties are very rare because of the limited compatibility of multiple photoresponsive functionality in a single system. In this work, the electron‐transfer (ET) and crystal engineering strategies were utilized to predesign CHPMs with multiple photoresponsive properties via the collaboration of paramagnetic metal ion (Dy3+), electron‐donor (ED) ligand (benzene‐1,2,3‐tricarboxylic acid, H3BTA) and electron‐acceptor (EA) ligand (1,10‐phenanthroline, phen). The resulting complex [Dy(BTA)(phen)2]⋅2H2O (1) shows hybrid chain with the intrachain Dy3+ ions bridged and chelated by tricarboxylate and phen ligands, respectively. After photostimuli, the ET between tricarboxylate and phen results in photogenerated radicals and the resultant quadruple photoresponsive properties. Considering the abundant resources of paramagnetic metal ions, ED‐ and EA‐ligands, this work provides a general method to construct CHPMs with multiple photoresponsive performances via the collaboration of each unit under the guidance of ET and crystal engineering strategies. [ABSTRACT FROM AUTHOR]

The production of photo‐switchable molecular nanomagnets with substantial coercivity, which is indispensable for information storage and process applications, is challenging. Introducing photo‐responsive spin‐crossover units provides a feasible means of controlling the magnetic anisotropy, interactions, and overall nanomagnet properties. Herein, we report a cyanide‐bridged chain 1⋅12H2O ({[(PzTp)FeIII(CN)3]2FeII(Pmat)2}n⋅12 H2O) generated by linking the FeII‐based spin‐crossover unit with the [(PzTp)Fe(CN)3]− (PzTp: tetrakis(pyrazolyl)borate) building block in the presence of asymmetric ditopic ligand Pmat ((4‐pyridine‐4‐yl)methyleneamino‐1,2,4‐triazole). Structural characterization revealed that the introduction of this asymmetric ligand led to a distorted coordination environment of FeII ions, which were equatorially coordinated by four cyanide N atoms, and apically coordinated by one pyridine N atom and one triazole N atom. Upon 808‐nm light irradiation, 1⋅12H2O underwent photoinduced spin‐crossover and exhibited single‐chain magnet behavior with a coercive field of up to 1.3 T. This represents a 3d‐based photoinduced single‐chain magnet exhibiting pronounced hysteresis. [ABSTRACT FROM AUTHOR]

The photogeneration of stable radicals is important but still challenging in the field of optical switching, displays, and other devices. Herein, crystalline 9-anthracene carboxylic acid (9-AC) and a mononuclear complex constructed from this ligand were for the first time discovered to show radical-induced photochromism and photomagnetism after Xe lamp light irradiation. This study finds a simple radical-actuated photochromic molecule for constructing a novel system of photochromic materials. [ABSTRACT FROM AUTHOR]

A Dy(III)-based linear chain compound was reported with an eye-detectable and reversible photochromic phenomenon under ambient conditions. After light irradiation, room temperature luminescence response and photodemagnetization effects appeared for the first time via regulation of radicals, showing a radical-switchable property in electron transfer photochromic materials. [ABSTRACT FROM AUTHOR]

Cryo-magnetic coolants based on the magnetocaloric effect (MCE) usually need relatively large fields to achieve practical cooling performance. Thus, it is important to hunt for molecular cryo-magnetic coolants with superior performance of the MCE under low fields (smaller than 2 T), considering the readily attainable low fields from commercialized Nd–Fe–B permanent magnets. In this work, the crystal structure, magnetic susceptibility and isothermal magnetization for two hybrid Gd-complexes, (NH4)[Gd(C2O4)(SO4)(H2O)] (1) and [Gd(C2O4)0.5(CO3)(H2O)] (2), cobridged by organic and inorganic ligands, were solvothermally synthesized and magnetically characterised, with the goal of obtaining novel molecular cryo-magnetic coolants. For 1, the sulfate bridges GdIII ions to generate inorganic chains as supramolecular building blocks (SBBs), which are further connected by the oxalate to result in the final host anionic architecture with an ammonium ion as the guest to balance the charge. For 2, the carbonate bridges GdIII ions to form inorganic layers as SBBs, which are further linked by the oxalate to give birth to the resultant pillar-layer structure. Because the merits of organic oxalate ligands and inorganic ligands (sulfate and carbonate) work together, the resultant compounds show a weak magnetic exchange interaction, a low molecular weight and a dense frame structure, and the observed maximum entropy change (−ΔSmaxm) is up to 42.4 J kg−1 K−1 for 1 at ΔH = 7 T and T = 2 K and 50.7 J kg−1 K−1 for 2 at ΔH = 7 T and T = 4 K, beyond the performance of commercialized gadolinium gallium garnet Gd3Ga5O12 (GGG, −ΔSmaxm = 38.4 J kg−1 K−1 with ΔH = 7 T). Notably, the −ΔSmaxm still reaches 25.2 J kg−1 K−1 for 1 and 26.8 J kg−1 K−1 for 2 at T = 2 K and ΔH = 2 T, and 32.3 J kg−1 K−1 for 1 and 33.3 J kg−1 K−1 for 2 at T = 2 K and ΔH = 3 T, which already outperform GGG (about 24 J kg−1 K−1 with ΔH = 3 T) and make them excellent cryo-magnetic refrigerants for low-temperature applications, even under low external fields. [ABSTRACT FROM AUTHOR]

Two novel photochromic and photomagnetic complexes actuated by nonphotochromic ligands have been hydrothermally synthesized through the pillar-layer strategy. After Xe lamp irradiation at room temperature, compound 1 shows naked-eye detectable photochromism, while 2 exhibits an efficient photodemagnetization effect. [ABSTRACT FROM AUTHOR]

Electron transfer in solid is crucial to switchable magnetic, electrical, optical and mechanical properties. However, it is a formidable challenge to control electron-transfer behaviors via manipulation of crystalline phases, especially through dynamic crystalline transformation. Herein, three crystalline phases of an {Fe2Co2} compound were obtained via enhancement of intermolecular π···π interactions inducing successive single-crystal-to-single-crystal transformations, from solvated 1·2CH3OH·4H2O, to desolvated 1 and its polymorph 1a accompanying electron transfer. 1·2CH3OH·4H2O showed thermally induced reversible intermetallic electron transfer in mother liquor. No electron-transfer behavior was observed in 1. 1a showed reversible intermetallic electron transfer upon thermal treatment or alternative irradiation with 808- and 532-nm lasers at cryogenic temperatures. The electron-transfer behaviors significantly change the magnetic and optical properties, providing a strategy to realize different electron-transfer behaviors and switchable functions via π···π interactions manipulated dynamic crystalline transformation. [ABSTRACT FROM AUTHOR]

Tuning of the spin crossover (SCO) behavior through paramagnetic building blocks with different steric hindrance effects is of great interest in terms of the synergy between SCO and magnetic interactions. Herein, the steric effect of specified FeIII building blocks is modified, from the large Tp* (hydridotris(3,5-dimethylpyrazol-1-yl)borate) analogue to a small Tp (hydrotris(pyrazolyl)borate) derivative; the FeII SCO unit and FeIII paramagnetic ions are incorporated into three well isolated trinuclear complexes featuring thermally induced and light-induced SCO properties. Reanalysis of the structures reveals that π-π stacking interactions play a key role in the thermal hysteresis and anomalous octahedral distortion parameter Σ around the FeII ion. The Tp* ligand showing the largest steric hindrance induces elongated FeII−N bond lengths and bending of the C≡N−FeII angle in 1, as well as having a relatively large electron donor effect, which leads to the lowest thermal transition temperature among the three compounds. [ABSTRACT FROM AUTHOR]

It is an ongoing challenge to design and synthesize magnetic materials that undergo colossal thermal expansion and that possess potential applications as microscale or nanoscale actuators with magnetic functionality. A paramagnetic metallocyanate building block was used to construct a cyanide-bridged Fe-Co complex featuring both positive and negative colossal volumetric thermal-expansion behavior. A detailed study revealed that metal-to-metal charge transfer between 180 and 240 K induced a volumetric thermal expansion coefficient of 1498 MK−1 accompanied with hysteretic spin transition. Rotation of the magnetic building blocks induced change of π⋅⋅⋅π interactions, resulting in a negative volume expansion coefficient of −489 MK−1, and another hysteretic magnetic transition between 300 and 350 K. This work presents a strategy for incorporating both colossal positive and negative volumetric thermal expansion with shape and magnetic memory effects in a material. [ABSTRACT FROM AUTHOR]

It is a challenge to reversibly switch both magnetism and polarity using light irradiation. Herein we report a linear Fe2Co complex, whereby interconversion between FeIIILS(μ-CN)CoIIHS(μ-NC)FeIIILS (LS=low-spin, HS=high-spin) and FeIIILS(μ-CN)CoIIILS(μ-NC)FeIILS linkages could be achieved upon heating and cooling, or alternating laser irradiation at 808 and 532 nm. The electron spin arrangement and charge distribution were simultaneously tuned accompanying bidirectional metal-to-metal charge transfer, providing switchable polarity and magnetism in the complex. [ABSTRACT FROM AUTHOR]

The sensitivity of the cumulative distribution function (CDF) of the response with respect to the input parameters is studied in this work, to quantify how the model output is affected by input uncertainty. To solve the response CDF sensitivity more efficiently, a novel method based on the sparse grid integration (SGI) is proposed. The response CDF sensitivity is transformed into expressions involving probability moments, which can be efficiently estimated by the SGI technique. Once the response CDF sensitivity at one percentile level of the response is obtained, the sensitivity values at any other percentile level can be immediately obtained with no further call to the performance function. The proposed method finds a good balance between the computational burden and accuracy, and is applicable for engineering problems involving implicit performance functions. The characteristics and effectiveness of the proposed method are demonstrated by several engineering examples. Discussions on these examples have also validated the significance of the response CDF sensitivity for the purpose of variable screening and ranking. [ABSTRACT FROM PUBLISHER]

A cyano-bridged ferromagnetic {Fe III 2 Fe II } alternating chain {[Fe III (pzTp)(CN) 3 ] 2 [Fe II (imidazole)(H 2 O)]}·3H 2 O ( 1 ) (pzTp = tetrakis(pyrazolyl)borate) was synthesized via rational design. Crystal structure analysis studies demonstrated that complex 1 had a one-dimensional double zigzagging chain-like structure. Magnetic measurements showed that ferromagnetic interactions dominate in 1 and the AC magnetic susceptibility revealed two limit regimes in accordance with the single chain magnet and spin-glass behavior. [ABSTRACT FROM AUTHOR]

Abstract Three one-dimensional (1D) cyanide-bridged heterobimetallic chains {[FeIII(Tp)(CN) 3 ] 2 CoII(mep) 2 }·2CH 3 OH (1 ; Tp = hydrotris(pyrazolyl)borate, mep = 4‑[(1 E)‑2‑(4‑Methylphenyl)ethenyl]pyridine), {[FeIII(Tp)(CN) 3 ] 2 CoII(eep) 2 }·2CH 3 OH (2 ; eep = 4‑[(1 E)‑2‑(4‑Ethylphenyl)ethenyl]pyridine) and {[FeIII(Tp)(CN) 3 ] 4 CoII 2 (nep) 4 }·3H 2 O·CH 3 OH (3 ; nep = 4‑[(1 E)‑2‑(2‑Naphthalenyl)ethenyl]pyridine) have been synthesized via self-assembly of the same [FeIII(Tp)(CN) 3 ]− unit and CoII ion in the presence of different N -substituted pyridine ligands. Magnetic measurements reveal that complex 1 exhibits ferromagnetic interactions and a long-range magnetic ordering below 3.5 K. Complex 2 shows antiferromagnetic long-range ordering below 3.3 K, while complex 3 shows a typical ferrimagnetic coupling at low temperatures. These results highlight the significant influence of the coligands on their magnetic properties. Graphical abstract Three one-dimensional cyanide-bridged {FeIII 2 CoII} n chains with different N -substituted pyridine ligands were synthesized and characterized. Magnetic measurements reveal that complex 1 exhibits ferromagnetic interactions and a long-range magnetic ordering. Complex 2 shows antiferromagnetic long-range ordering, while complex 3 shows a typical ferrimagnetic coupling. The alteration of the coligands greatly influences the magnetic coupling interactions and finally results in different magnetic properties. Unlabelled Image Highlights • Three one-dimensional cyanide-bridged {FeIII 2 CoII} n chains were synthesized. • Magnetic measurements indicated that three compounds displayed completely different behavior. • The alteration of the coligands results in different magnetic properties. [ABSTRACT FROM AUTHOR]

The preparation, single-crystal X-ray crystallography and magnetic properties are reported for two single-zigzag chain complexes {[W(CN) 8 ][Ni(imi) 4 ]}·Bu 4 N·CH 3 OH·2H 2 O ( 1 ) and {[Mo(CN) 8 ][Ni(imi) 4 ]}·Bu 4 N·2H 2 O ( 2 ) (imi = imidazole, Bu = normal-butyl). The structure studies reveal that both complexes feature one-dimension anion chains linked by [W(CN) 8 ] 3 − units in 1 or [Mo(CN) 8 ] 3 − units in 2 . Magnetic studies show that strong ferromagnetic exchange is operative within the W V (μ-CN)Ni II units for ( 1 ) and Mo V (μ-CN)Ni II units for ( 2 ). [ABSTRACT FROM AUTHOR]

It is a challenge to tune the magnetic properties of 1D complex via balancing the intra- and interchain magnetic interactions. Utilizing tricyanometalate precursors with different steric hindrance to react with Cu II in the presence of 4-styrylpyridine or 4-cyanopyridine, respectively, two cyano-bridged {Fe 2 Cu} double-zigzag chains [Fe III (Tp)(CN) 3 ] 2 Cu II (4-styrylpyridine) 2 ·3CH 3 CN·3H 2 O (Tp = hydrotris(pyrazolyl)borate) ( 1 ) and [Fe III (pzTp)(CN) 3 ] 2 Cu II (4-cyanopyridine) 2 ·2CH 3 CN·H 2 O (pzTp = tetrakis(pyrazolyl)borate) ( 2 ) were obtained. 1 shows metamagnetism with a critical field of 700 Oe, whereas 2 shows the coexistence of metamagnetism and single-chain magnet behavior. [ABSTRACT FROM AUTHOR]

Two hexanuclear complexes of formula [Fe III (Tp*)(CN) 3 ] 4 [Fe II (tptz)] 2 ( 1 ), [Fe III (Tp*)(CN) 3 ] 4 [Co II (tptz)] 2 ( 2 ) [Tp* = hydridotris(3,5-dimethylpyrazolyl)borate, tptz = (2,4,6-tris-(2-pyridyl)1,3,5-triazine] have been synthesized via directional assembly of metallocyanate precursor and metal cationic ions. The magnetic properties characterization indicate that ferromagnetic interactions dominate in the two complexes, resulting in a spin ground state of S = 5 and S = 6, respectively. [ABSTRACT FROM AUTHOR]