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Herein, we report a twisted cubic Cu(I)4Ti(IV)4-oxo cluster stabilized by in situ – formed 2,2′-biphenolate ligands from the oxidative coupling of phenols. The 2,2′-biphenolate-functionalized Cu(I)4Ti(IV)4O4 cluster shows short Cu⋯C contacts and exhibits smaller HOMO–LUMO gaps than those of reported Ti(IV)4O4. [ABSTRACT FROM AUTHOR]

A tetradentate ligand, 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethene (TPPE), was adopted to construct a two-dimensional coordination polymer that incorporated valence tautomerism and luminescence, and the synergistic effect arising from energy transfer from TPPE to the semiquinone moieties was experimentally and theoretically uncovered. [ABSTRACT FROM AUTHOR]

Spin-crossover (SCO) materials have been extensively investigated in the past few decades with promising applications in a wide range of fields including displays, sensors, and storage components. The introduction of secondary physical properties to SCO materials resulting in bifunctional materials is becoming a research hot spot. In particular, for the fluorescent SCO materials, fluorescence can serve as a sensitive probe that easily expresses the spin-state changes of SCO materials; therefore, fluorescent SCO bifunctional materials have promising applications in the fields of magneto-optical switching and information processing. In this perspective, we briefly review the main synthetic strategies and progresses in fluorescent SCO materials in the last twenty years. [ABSTRACT FROM AUTHOR]

We report a phosphine-directed ruthenium-catalyzed C8-selective alkylation of naphthalenes with alkenes. This protocol provides straightforward access to a large library of electron-rich C8-alkyl substituent 1-naphthphosphines, which outperformed common commercial phosphines and their precursors in the Pd-catalyzed Suzuki–Miyaura coupling of aryl bromides with alkylboronic acid. [ABSTRACT FROM AUTHOR]

A series of dynamic single crystals with a chemical formula of [MII(en)3]SO4 (en = ethylene and MII = NiII, MnII, and CdII) was synthesized. As the temperature decreases, these materials exhibit dielectric switching in the vicinity of the phase transition point accompanied by anisotropic thermal expansion in the cell parameters as a consequence of the order–disorder structural change of SO 2−4 in a cavity surrounded by five [MII(en)3]2+ complex cations. Because the variation of metal centers with different ionic radii changes the shape of the complex cation, which affects the distribution of hydrogen-bond interactions around the SO 2−4 , the dynamic motion of SO 2−4 is substantially tuned. Correspondingly, the dielectric properties and anisotropic thermal expansion of materials were largely shifted, especially in the single crystals of [MnII(en)3]SO4, whose structural change is distinctly different from the crystals of Ni(II) and Cd(II). The detailed structural mechanism accounting for the different physical properties of these materials was discussed. [ABSTRACT FROM AUTHOR]

Further towards the fast, continuous, efficient and scaled-up production of energetic cocrystals, a microchannel-confined crystallization strategy has been developed to prepare a high-quality CL-20/HMX cocrystal with desired shape and size. Applying the flow-focusing microchannel, the mixing efficiency of solution and antisolvent and supersaturation were facilely regulated through changing the solution concentration and flow rate ratio of the solution and antisolvent. At the solution concentration of 0.25 mol L−1 and flow rate ratio of 1 : 6, a pure CL-20/HMX cocrystal with a cube-shaped appearance and a particle diameter D (4, 3) of 21.8 μm has been obtained, overcoming the problem easy to crystallize in platelet morphology. This cocrystal presents a sharp decomposition within a very narrow temperature range (245.1 °C to 246.2 °C) and a peak temperature of 245.4 °C, close to that of raw CL-20, showing a quick energy release rate. TG-FTIR and thermal analysis illustrate that its thermal behavior under isothermal conditions is determined by the decomposition of the least stable CL-20 molecules. A high density of 1.9552 ± 0.0014 g cm−3 at room temperature, few internal defects and friction impact sensitivity, even lower than that of raw HMX, mean high crystal quality of the CL-20/HMX cocrystal. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Correction for 'Multiple correlations between spin crossover and fluorescence in a dinuclear compound' by Chun-Feng Wang et al., Chem. Commun., 2016, 52, 14322–14325, https://doi.org/10.1039/C6CC07810A. [ABSTRACT FROM AUTHOR]

A single crystal composed of one-dimensional coordinated polymers, [CdCl 2 (1-methyl-2-pyridone)] n , has been synthesized and characterized. This compound exhibits outstanding elastic bending due to the molecular spring nature of the CdCl 2 coordination framework and weak intermolecular interactions between the coordination chains. Owing to the helical arrangement of organic ligands surrounding the coordination structure, the compound crystallizes in a chiral space group. As a result, it displays compelling circular dichroism spectra and second harmonic generation properties.

In this paper, we report a two-dimensional (2D) Hofmann-type spin-crossover coordination polymer [Fe II ( o -NTrz) 2 Pt II (CN) 4 ]·H 2 O ( o -NTrz = 4-( o -nitrobenzyl)imino-1,2,4-triazole). Due to the remarkable configurational flexibility of triazole-based ligand, the porous structure of this compound can be reversibly regulated by the loss of guest water molecules as a consequence of rotation of o -NTrz. The 180° reorientation of the o -nitrobenzyl moiety not only induces a response of gate-closing/opening of the porous framework but also significantly modulates the spin transition temperature. The present investigation highlights the potential of Hofmann-type SCO compounds with flexible ligands in exploring unusual physical and chemical phenomena.

Herein, we report a twisted cubic Cu(I) 4 Ti(IV) 4 -oxo cluster stabilized by in situ - formed 2,2'-biphenolate ligands from the oxidative coupling of phenols. The 2,2'-biphenolate-functionalized Cu(I) 4 Ti(IV) 4 O 4 cluster shows short Cu⋯C contacts and exhibits smaller HOMO-LUMO gaps than those of reported Ti(IV) 4 O 4 .

Spin-crossover (SCO) materials have been extensively investigated in the past few decades with promising applications in a wide range of fields including displays, sensors, and storage components. The introduction of secondary physical properties to SCO materials resulting in bifunctional materials is becoming a research hot spot. In particular, for the fluorescent SCO materials, fluorescence can serve as a sensitive probe that easily expresses the spin-state changes of SCO materials; therefore, fluorescent SCO bifunctional materials have promising applications in the fields of magneto-optical switching and information processing. In this perspective, we briefly review the main synthetic strategies and progresses in fluorescent SCO materials in the last twenty years.

We report a phosphine-directed ruthenium-catalyzed C8-selective alkylation of naphthalenes with alkenes. This protocol provides straightforward access to a large library of electron-rich C8-alkyl substituent 1-naphthphosphines, which outperformed common commercial phosphines and their precursors in the Pd-catalyzed Suzuki-Miyaura coupling of aryl bromides with alkylboronic acid.

A series of dynamic single crystals with a chemical formula of [M II (en) 3 ]SO 4 (en = ethylene and M II = Ni II , Mn II , and Cd II ) was synthesized. As the temperature decreases, these materials exhibit dielectric switching in the vicinity of the phase transition point accompanied by anisotropic thermal expansion in the cell parameters as a consequence of the order-disorder structural change of SO2-4 in a cavity surrounded by five [M II (en) 3 ] 2+ complex cations. Because the variation of metal centers with different ionic radii changes the shape of the complex cation, which affects the distribution of hydrogen-bond interactions around the SO2-4, the dynamic motion of SO2-4 is substantially tuned. Correspondingly, the dielectric properties and anisotropic thermal expansion of materials were largely shifted, especially in the single crystals of [Mn II (en) 3 ]SO 4 , whose structural change is distinctly different from the crystals of Ni(II) and Cd(II). The detailed structural mechanism accounting for the different physical properties of these materials was discussed.

A mononuclear complex with long alkyl chains, [Fe II (H 2 Bpz 2 ) 2 (C 9 bpy)] (1; H 2 Bpz 2 = dihydrobis(1-pyrazolyl)borate, C 9 bpy = 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.