Triboluminescent spectrum and crystal structure of a europate complex with the most intensely triboluminescent emission at ambient temperature

Mechanoluminescence Rebrightening the Prospects of Stress Sensing: A Review

The emergence of new applications, such as in artificial intelligence, the internet of things, and biotechnology, has driven the evolution of stress sensing technology. For these emerging applications, stretchability, remoteness, stress distribution, a multimodal nature, and biocompatibility are important performance characteristics of stress sensors. Mechanoluminescence (ML)-based stress sensing has attracted widespread attention because of its characteristics of remoteness and having a distributed response to mechanical stimuli as well as its great potential for stretchability, biocompatibility, and self-powering. In the past few decades, great progress has been made in the discovery of ML materials, analysis of mechanisms, design of devices, and exploration of applications. One can find that with this progress, the focus of ML research has shifted from the phenomenon in the earliest stage to materials and recently toward devices. At the present stage, while showing great prospects for advanced stress sensing applications, ML-based sensing still faces major challenges in material optimization, device design, and system integration.

Triboluminescence Phenomenon Based on the Metal Complex Compounds-A Short Review

Triboluminescence (TL) is a phenomenon of light emission resulting from the mechanical force applied to a substance. Although TL has been observed for many ages, the radiation mechanism is still under investigation. One of the exemplary compounds which possesses triboluminescent properties are copper(I) thiocyanate bipyridine triphenylphosphine complex [Cu(NCS)(py)₂(PPh₃)], europium tetrakis dibenzoylmethide triethylammonium EuD₄TEA, tris(bipyridine)ruthenium(II) chloride [Ru(bpy)₃]Cl₂, and bis(triphenylphosphine oxide)manganese(II) bromide Mn(Ph₃PO)₂Br₂. Due to the effortless synthesis route and distinct photo- and triboluminescent properties, these compounds may be useful model substances for the research on the triboluminescence mechanism. The advance of TL studies may lead to the development of a new group of sensors based on force-responsive (mechanical stimuli) materials. This review constitutes a comprehensive theoretical study containing available information about the coordination of metal complex synthesis methodologies with their physical, chemical, and spectroscopic properties.

Crystal structures and intense luminescence of tris(3-(2′-pyridyl)-pyrazolyl)borate Tb3+ and Eu3+ complexes with carboxylate co-ligands

The carboxylate coligands affect the bright luminescence of a series of Eu³⁺ and Tb³⁺ complexes.

Chiral six-coordinate Dy(iii) and Tb(iii) complexes of an achiral ligand: structure, fluorescence, and magnetism

Two new chiral six-coordinate lanthanide complexes are obtained using an achiral ligand. Complex [Zn₃Dy] displays field-induced slow magnetization relaxation, while complex [Zn₃Tb] exhibits intense green photofluorescence and triboluminescence.

Triboluminescence and crystal structure of the complex [Eu(NО3 )3 (HMPA)3 ]: role of cleavage planes

The atomic structure of crystals of the [Eu(NО₃ )₃ (HMPA)₃ ] [hexamethylphosphotriamide (HMPA)] complex characterized by an intensive luminescence and triboluminescence was determined using X-ray structural analysis. Noncentrosymmetric crystals have a monoclinic syngony: a = 16.0686 (3), b = 11.0853 (2), c = 20.9655 Å (4), β = 93.232° (1), space group P2₁ , Z = 4, ρ_calc  = 1.560 g/cm³_. The crystal structure is represented by individual С₁₈ Н₅₄ EuN₁₂ O₁₂ P₃ complexes linked through van der Waals interactions with clearly expressed cleavage planes. The Eu(III) atom coordination polyhedron reflected the state of a distorted square antiprism. Structural aspects of the suggested model, including formation of triboluminescence properties, were considered and the role of the cleavage planes was discussed.

A Second-Order Nonlinear Optical Material Prepared through In Situ Hydrothermal Ligand Synthesis

The in situ hydrothermal reactions of ZnCl(2) with benzonitrile, 2-amino-5-cyanopyridine, and trans-2,3-dihydro-2-(4' '-cyanophenyl)-benzo[e]indole in the presence of NaN(3) and water afford two 3D-diamond-like networks, (CN(4)-C(6)H(5))(2)Zn (1) and (NH(2)-C(5)H(3)N-CN(4))(2)Zn (2), and one 2D square grid network, [(CN(4)-C(6)H(4)-C(12)H(7)N-C(5)H(4)N)(2)Zn].1.5H(2)O (3), in which these ligands gradually involve a noncenter-A-D (acceptor-donor) system, a one-center-A-D system, and a two-center-A-D system, respectively. All three compounds crystallize in noncentrosymmetric space groups (I2d for 1 and 2 and Fdd2 for 3) and display strong second harmonic generation (SHG) responses. Among the three new complexes, 3 shows the largest SHG effect, which is about 50 and 500 times that of urea and KDP (KH(2)PO(4)), respectively. The two-center-A-D system (multicenter push-pull electronic effect) in 3 may be responsible for it having the largest SHG effect. Interestingly, the three compounds exhibit strong fluorescent emissions at different wavelengths, 1 and 2 with blue fluorescent emissions at 390 and 415 nm and 3 with yellow-green fluorescent emissions at 495 and 532 nm.

The First Metal (Nd3+, Mn2+, and Pb2+) Coordination Compounds of 3,5-Dinitrotyrosine and their Nonlinear Optical Properties

The reactions of 3,5-dinitrotyrosine (H2DNTY) with Nd(NO3)3.6H2O, Mn(ClO4)2.6H2O, and Pb(OAc)2 afforded three homochiral compounds: discrete [Nd(Hdnty)2(NO3)(H2O)5].3H2O (1) and two- and three-dimensional coordination polymers, [Mn(Hdnty)2] (2) and [Pb(dnty)(0.5 H2O)] (3), respectively. The Nd atom in 1 displays a tricapped trigonal prism and supramolecular weak interactions, such as pi-pi stacking and H-bonds, between amino and nitro groups result in the formation of a three-dimensional network through these interactions. 2 has a two-dimensional square-grid topological net while 3 has the first three-dimensional homochiral ThSi2 net. To the best of our knowledge, these are the first metal coordination compounds with 3,5-dinitrotyrosine. Preliminary second harmonic generation (SHG) investigations indicated that 1 and 2 are SHG active with estimated responses 5 and 6 times larger than that of urea, respectively, while 3 is SHG non-active (obeying the Klainman symmetry requirement). Strong enhancement of their SHG efficiency, compared with H2DNTY, may be due to 1) the addition of a good donor-pi-acceptor organic chromophore into the compound resulting in superior qualities of both inorganic and organic materials and 2) the H-bonds that persist in them. Crystal data: 1: C18H32N7O25Nd, Mr = 890.75 g mol(-1), monoclinic, P2(1), a=7.0179(7), b=27.060(3), c=8.3097(8) A, alpha=gamma=90.00, beta=95.646(2) degrees , V=1570.4(3) A(3), Z=2, rho(calcd)=1.884 Mg m(-3), R(1)=0.0489, wR(2)=0.1223, mu=17.67 mm(-1), S=0.811, Flack value=0.003(13); 2: C(18)H(16)N(6)O(14)Mn, M(r)=595.31 g mol(-1), orthorhombic, P2(1)2(1)2, a=8.4381(14), b=13.639(2), c=19.697(3) A, alpha=beta=gamma=90.00 degrees , V=2266.9(6) A(3), Z=4, rho(calcd)=1.744 Mg m(-3), R(1)=0.0866, wR(2)=0.2030, mu=6.72 mm(-1), S=1.095, Flack value=0.02(6); 3: C(9)H(8)N(3)O(7.5)Pb, M(r)=485.37 g mol(-1), tetragonal, P4(1)2(1)2, a=12.8136(12), b=12.8136(12), c=14.931(2), alpha=beta=gamma=90.00 degrees , V=2451.5(5) A(3), Z=8, rho(calcd)=1.885 Mg m(-3), R(1)=0.0564, wR(2)=0.1323, mu=6.942 mm(-1), S=0.878, Flack value=0.03(2). For space group P4(3)2(1)2: R(1)=0.0672, wR(2)=0.1656, S=1.034, Flack value=1.02(3); this suggests the chosen space group P4(1)2(1)2 is correct.

Strong enhancement of second-harmonic generation (SHG) response through multi-chiral centers and metal-coordination

The hydrothermal reaction of CdCl2 with L (L =trans-2,3-dihydro-2-(4'-pyridyl)-3-(3"-cyanophenyl)benzo[e]indole) in the presence of NaN3 and water offers a novel route to [Cd(L-N3)2(H2O)2]n, a 1D infinite molecular box with approximate dimensions 10.37 x 6.64 è; 1 is shown to display a very strong SHG response that is 80 times that observed for urea.

A Novel TGS-like Inorganic−Organic Hybrid and a Preliminary Investigation of Its Possible Ferroelectric Behavior

The homochiral inorganic-organic hybrid compound (H(3)NHPA)(SnCl(3))(2)(H(2)O)(3) [1, (S)-4-(4'-aminophenyl)-2-aminobutanoic acid diammonium trichloride stannite triaqua] has a TGS (triglycine sulfate)-like structure. Preliminary investigation suggests a possible ferroelectric behavior with a saturation spontaneous polarization (P(s)) of ca. 3.5 microC.cm(-)(2), which is slightly greater than that of TGS (P(s) = 3.0 microC.cm(-)(2)).