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The study about the effect of the stacking mode on the photo/electrical performance of crystalline organic/inorganic hybrids will be beneficial for the design of new photo/electrically active materials. In this work, D–π–A stilbazolium-type chromophores bearing novel ortho-N-alkyl substituents were synthesized and incorporated with iodoargentates to generate three crystalline stilbazolium/iodoargentate hybrids, i.e., [(CMAMP)(Ag2I3)]n (1), [(HMAMP)(Ag2I3)]n (2), and [(HMAHP)2(Ag5I7)]n (3). When the substitutes on the amine group range from –C2H5CN (for CMAMP+) to –C2H5OH (for HMAMP+), the same (Ag2I3)nn− anions will be produced, and the π⋯π stacking interactions among stilbazoliums will be observed from absence to presence (weak head-to-head H-aggregation). Furthermore, when the substituent on the ortho-N of pyridine was also set as –C2H5OH (for HMAHP+), more electron-rich (Ag5I7)n2n− anion can be generated, and strong head-to-tail H-aggregation among HMAHP+ cations will happen. The enhanced aggregation strengthening in 3 can lead to its larger blue-shift photoluminescence, higher photocurrent, and better resistive switching performance (much higher ON/OFF ratio of 4.51 × 102). Their binary resistive switching mechanism can be explained as the SCLC model, and the better photo/electrical performances of 3 stem from its stronger head-to-tail H-aggregations, more negatively charged (Ag5I7)n2n− anion, and stronger (Ag5I7)n2n−–HMAHP+ interaction. The highly delocalized π antibonding orbitals between the empty p-orbitals of ethylene in its LUMO of (HMAHP)22+ dimer of 3 also support this conclusion. The good structure–property correlation based on accurate structural information in these stilbazolium/iodoargentate hybrids will be beneficial for the design of next-generation memory devices. [ABSTRACT FROM AUTHOR]

Two new copper(I) iodide-based hybrids, i.e. (Py3P–O–PPy3)(Cu2I4) (1) and (Py3P–O–PPy3)(Cu4I6) (2) (Py = pyrrolidine), have been prepared, in which the tripodal diphosphonium (Py3P–O–PPy3)2+ is in situ generated in the one-pot synthesis. The disordered (Cu4I6)2− tetramers are rare with two sets of tetracuprate centers. Interestingly, 1 exhibits sensitive luminescence mechanochromism, which is ascribed to the disturbed cuprophilic Cu⋯Cu interactions and the crystalline packing adjustment by destroying C–H⋯I hydrogen bonds during mechanical force. In particular, the luminescence thermochromism is unique, whose fluorescence intensity is strengthened with the elevated temperature. This could be due to the S2–S1 internal conversion on the linear P–O–P backbone, which will be bent upon heating. Simultaneous luminescence thermo/mechanochromism can also be monitored in 1. However, no luminescence thermo/mechanochromic performances can be detected in 2, so the luminescence thermo/mechanochromism of 1 could be quenched with DMF. The conclusions in this work might provide a new large-scale synthesis strategy for intelligent responsive luminescent materials. [ABSTRACT FROM AUTHOR]

Studies on the recycling of uranium, such as its usage as new materials, can promote the safe treatment of nuclear waste. In this work, with the direction of transition-metal complex cations, three uranyl–organic frameworks (UOFs) with different dimensions have been synthesized via a hydrothermal reaction, i.e. [Cu(phen)2(SO4)(UO2)(TDC)·H2O]n (1), {[Zn(phen)3][(UO2)2(TDC)3(TDC)]·6H2O}n (2), and {[Cd(phen)3][(UO2)2(TDC)2(OX)·2H2O]}n (3), (TDC = thiophene-2,5-dicarboxylic acid, OX = oxalate, and phen = 1,10-phenanthroline). With the presence of SO42−, 1 presents a rare neutral 1-D Cu/U heterometallic chain. Under the similar [Zn(phen)3]2+ and [Cd(phen)3]2+ templates, 2 is a 2-D [(UO2)2(TDC)3]n planar non-interpenetrated honeycomb layer, but 3 presents an interesting twofold interpenetrated (6,3) sheet structure, which is led by the larger cavity of the hexagonal motif with the presence of the second ligand OX. This trend could be helpful for the oriented construction of UOFs. Intra- and inter-layer hydrogen bonds between the honeycomb structure and guest cations and π–π stacking interactions contribute to the stabilization of the overall framework. Complete quenching of uranyl luminescence via nonradiative decay can be observed in 1, and 2 and 3 emit yellow fluorescence with well-resolved vibronic fine structures. The interpenetrated arrangements could give rise to weakened uranyl emission. [ABSTRACT FROM AUTHOR]

Strong electron-poor cation diphenyliodonium was firstly incorporated with transition metal thiocyanates to obtain three new photo-sensitive hybrids, (DPI)3[Mn(SCN)5(H2O)]·0.25H2O (α-1), {(DPI)2[Ni(SCN)4]}n (α-2) and {(DPI)6[Cd3(SCN)12]}n (α-3) (DPI+ = diphenyliodonium), whose photo-induced structural transformations to corresponding β-phases have been disclosed. After irradiating, all the MX6 octahedrons stretch clearly along the M–S directions, and C–H⋯π interactions and the secondary hypervalent I(III)⋯S halogen bonds are weakened. The hydrogen bonds are also weakened, except for those in 1. Time-dependent solid-state UV-vis spectra, PXRD patterns and EPR spectra before and after irradiating were obtained to prove the irreversible structural transformations of the hybrids, during which minor structural adjustments occurred. Consequently, the fluorescence emission changed from blue (α-3) to yellow (β-3) upon irradiation. Interestingly, obvious photomagnetization on 1 with a χMT increase of 14.89% and photodemagnetization on 2 with a χMT decrease of 12.82% can be observed. Finally, these hybrids can be used as long-term inkless and erasable print media. This work demonstrates the potential application of diphenyliodonium-based hybrids in some photo-sensitive functional materials. [ABSTRACT FROM AUTHOR]

The combination of hexacyanoferrate anions with protonated N,N′-dipyridyl-naphthalene diimide tectons resulted in a novel cuboid 3-D H-bonded anion-coordinated framework. Induced by anion–π interactions, such a unique framework is further catenated into an unprecedented five-fold interpenetrated D–A hybrid heterostructure with 1-D hexacyanoferrate polyanions and naphthalene diimide aggregates as electron donors and acceptors, respectively. The photophysical and photochemical properties have also been discussed. [ABSTRACT FROM AUTHOR]

The mono-substituted bipyridinium derivative 1-(3-carboxybenzyl)-4,4′-bipyridinium (cbpy) and polyiodide were adopted to construct two new lead-carboxylate hybrids: [Pb(cbpy)I3·I3]n (1) and {[Pb(cbpy)2](I3)4·I2}n (2), in which interesting halogen bonds were detected. Specifically, the hybrids demonstrate efficient photocatalytic degradation of organic dyes and excellent photocurrent response, and the mechanisms of degradation have been discussed and verified using theoretical calculations. [ABSTRACT FROM AUTHOR]

The first transition-metal-bridged polyniobotungstate-based 3D framework has been hydrothermally synthesized, which is constructed from bi-[CuII(en)2(H2O)]-decorating [Nb3W3O19]5− polyoxoanions linked together by CuI ions. Interestingly, the 3D polyniobotungstate framework can undergo a solid–liquid reaction with KI solution to generate a 1D copper halide of [Cu(en)2][CuI2]2 in a single-crystal-to-single-crystal process. [ABSTRACT FROM AUTHOR]