Unraveling the Mechanisms of the Excited-State Intermolecular Proton Transfer (ESPT) for a D-π-A Molecular Architecture.

Precise revealing the mechanisms of excited-state intermolecular proton transfer (ESPT) and the corresponding geometrical relaxation upon photoexcitation and photoionization remains a formidable challenge. In this work, the compound (E)-4-(((4H-1,2,4-triazol-4-yl)imino)methyl)-2,6-dimethoxyphenol (TIMDP) adopting a D-π-A molecular architecture featuring a significant intramolecular charge transfer (ICT) effect has been designed. With the presence of perchloric acid (35 %), TIMDP can be dissolved through the formation of a HClO -H O-OH(TIMDP)-N(TIMDP) hydrogen-bonding bridge.

Porous High-Valence Metal-Organic Framework Featuring Open Coordination Sites for Effective Water Adsorption.

The design and preparation of a porous high-valence metal-organic framework (MOF) featuring open coordination sites are of utmost importance for the development of adsorbent materials. Here in this work, the three-dimensional (3D) high-valence MOF [Er(dcbp)(DMF)(HO)]·2HO (HV-MOF-1; Hdcbp = 4,4'-dicarboxy-2,2'-bipyridine, DMF = N,N-dimethylformamide), which possesses permanent porosity and two open coordination sites, has been prepared and characterized. In the 3D framework, the dcbp molecules display two different bridging styles, resulting in ordered diamondlike pores with bared carboxyl oxygen and pyridine nitrogen atoms on dcbp exposed directly to the pores, generating hydrophilic characteristics and high water affinity.

Ultralarge Dielectric Relaxation and Self-Recovery Triggered by Hydrogen-Bonded Polar Components.

Subtle integration of rotatable polar components into dielectric crystals can contribute significantly to adjustable switching temperatures ( T) and dielectric relaxation behaviors. Currently, one of the biggest challenges lies in the design of optimal polar components with moderate motion resistance in a crystalline system. In this work, we demonstrate that under refrigerator conditions, rotatable hydrogen-bonded one-dimensional (1D) cationic chains, {[CHN]} (CHN = 3,5-diamino-1,2,4-triazolinium), and two-dimensional (2D) anionic layers, {[(HO)·SO]} , can be generated in an organic salt, 3 ([CHN]·[(HO)·SO]).

Atomically Thin Two-Dimensional Nanosheets with Tunable Spin-Crossover Properties.

Combining the fascinating advantages of ultrathin two-dimensional (2D) nanosheets with the nanostructuration of spin-crossover (SCO) materials represents an attractive target of controlled fabrication of SCO nano-objects at the device level. Here, we demonstrate that through facile-operating ultrasonic force-assisted liquid exfoliation technology the three-dimensional (3D) van der Waals SCO bulk precursor {[Fe(1,3-bpp)(NCS)] (1, 1,3-bpp = 1,3-di(4-pyridyl)-propane)} can be exfoliated into single-layered 2D nanosheets (NS-1). As a consequence, the magnetism has been tuned from complete paramagnetic (bulk precursors) to SCO transition at around 250 K (2D nanosheets).

Single-Layered Two-Dimensional Metal-Organic Framework Nanosheets as an in Situ Visual Test Paper for Solvents.

Through a facile-operating ultrasonic force-assisted liquid exfoliation technology, the single-layered two-dimensional (2D) [Co(CNS)(pyz)] (pyz = pyrazine) nanosheets, with a thickness of sub-1.0 nm, have been prepared from the bulk precursors. The atomically thickness and the presence of abundant sulfur atoms with high electronegativity arrayed on the double surfaces of the sheets are making this kind of 2D MOF (metal-organic framework) nanosheets highly sensitive to intermolecular interactions.

Bidirectional Photoswitching via Alternating NIR and UV Irradiation on a Core-Shell UCNP-SCO Nanosphere.

Bidirectional photoswitching of molecular materials under ambient condition is of significant importance. Herein, we present for the first time that a core-shell UCNP-SCO nanosphere (UCNP = upconversion nanophosphor, SCO = spin crossover), which was composed of a UCNP core (NaYF: 20 mol % Yb, 1 mol % Er) and an SCO iron(II) shell ([Fe(HBpz)(bipy-COOH)], HBpz = dihydrobis(1-pyrazolyl)borate, bipy-COOH = 4,4'-dicarboxy-2,2'-bipyridine), can be reversibly photoswitched between the high-spin and low-spin states at room temperature in the solid state, via alternating irradiation with near-infrared (λ = 980 nm) and ultraviolet (λ = 310 nm) light. What's more, this reversible spin-state switching was accompanied by a variation of fluorescent spectrum and dielectric constants.

Thermal-Induced Dielectric Switching with 40K Wide Hysteresis Loop Near Room Temperature.

A thermal-induced dielectric switching has been realized in two ion-pair crystal [CHN]·[HPO] (1, CHN = 3,5-diamino-1,2,4-triazolinium) through single-crystal-to-single-crystal phase transition (SCSC-PT). Upon cooling from room temperature, the 1D cation stripes that are composed of [CHN] cations have undergone a 90° sharp rotation around the c axis, accompanied by the transition of crystal stacking from loose unparallel (dynamic state) to compression parallel (static state) and reorientation of dipoles on the [CHN] cation, which thus resulted in high dielectric state to low dielectric state transformation. While on the warming run, the reverse process was rather sluggish, resulting in a reversible dielectric switching with ultralarge (about 40K wide) hysteresis loop near room temperature.

Binding CO from Air by a Bulky Organometallic Cation Containing Primary Amines.

The organometallic cation 1 (Fe(bipy-NH), bipy-NH = 4,4'-diamino-2,2'-bipyridine), which was constructed in situ in solution, can bind CO from air effectively with a stoichiometric ratio of 1:4 (1/CO), through the formation of "H-bonded CO" species: [CO-OH-CO] and [CO-CO-OH]. These two species, along with the captured individual CO molecules, connected 1 into a novel 3D (three-dimensional) architecture, that was crystal 1·2(OH)·4(CO). The adsorption isotherms, recycling investigations, and the heat capacity of 1 have been investigated; the results revealed that the organometallic cation 1 can be recycled at least 10 times for the real-world CO capture applications.

A dosimetric and treatment efficiency evaluation of stereotactic body radiation therapy for peripheral lung cancer using flattening filter free beams.

To investigate potential dosimetric benefits and treatment efficiency of dynamic conformal arc therapy (DCA), intensity modulated radiation therapy (IMRT), and double partial arcs Rapidarc (RA) techniques in the treatment of early-stage peripheral lung cancer using stereotactic body radiotherapy (SBRT) with flattening filter free (FFF) beams. Twenty early-stage peripheral lung cancer patients were selected. For each patient, DCA, IMRT and RA plans were created to meet Radiation Therapy Oncology Group (RTOG) 0915 objectives with 48 Gy covering 95% of the planning target volume (PTV) in 4 fractions.

Dosimetric verification of stereotactic body radiation therapy for lung cancer treatment plans using flattening filter-free beams.

Aims: This study aimed to analyze the dose distribution using different dosimetric tools in conducting pretreatment quality assurance for lung cancer stereotactic body radiation therapy (SBRT) plans with flattening filter free (FFF) beams.

Methods: Nine patients with lung cancer treated via SBRT were randomly selected, and their treatment plans were generated using the Eclipse treatment planning system (TPS) with FFF beams. For each patient, the same plan was applied to the Delta4 phantom and MatriXX by the TPS, which calculated the dose distribution.