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1.
Discovering new deep‐ultraviolet (DUV) nonlinear optical (NLO) materials is currently a great challenge. The reported DUV NLO materials are almost exclusively borates or phosphates. Silicates—the largest constituent of the earth's crust—are excluded owing to their weak second harmonic generation (SHG) response. We report a silicate, Li2BaSiO4, with edge‐sharing LiO4–SiO4 tetrahedra that achieves the balance between a short UV absorption edge, below 190 nm, and a large SHG response, 2.8×KDP. The SHG intensity is the largest for silicates without second‐order Jahn–Teller cations, and exceeds that of non‐isomorphic Li2SrSiO4 by more than an order of magnitude. As such Li2BaSiO4 may be seen as a promising DUV‐UV NLO material. This research indicates that edge‐sharing tetrahedra is a new design parameter for discovering new DUV NLO materials.  相似文献   

2.
A series of open‐framework aluminoborates (ABOs) [M(dien)2][AlB6O11(OH)] (M=Co ( I a ), Ni ( I b ), Cd ( I c ), Zn ( I d ); dien=diethylenetriamine) and [M(en)3][AlB7O12(OH)2] ? (H2O)0.25 (M=Co ( II a ), Ni ( II b ); en=ethylenediamine) have been made under hydrothermal conditions and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, UV/Vis and fluorescence spectroscopy, powder X‐ray diffraction, single‐crystal X‐ray diffraction, and nonlinear optical determination. These compounds were classified as two structural types: Type I ( I a – d ) contains AlO4 tetrahedra and B6O11(OH) clusters, which link to form a new 3D framework with 7‐/9‐ring helical channels and large 13‐ring channels; whereas type II ( II a , b ) is composed of AlO4 tetrahedra, chainlike B4O6(OH)2 tetramer, and crablike B6O12 clusters, which interconnect to form other new 3D frameworks with 8‐ring helical channels, rare 16‐ring double‐helical channels, and larger odd 15‐ring channels. These compounds represent the first examples of 3D ABOs templated by transition‐metal complexes (TMCs). I c , d present good second harmonic generation (SHG) properties. UV/Vis spectral investigation indicates that I a – d and II a , b are wide‐band‐gap semiconductors.  相似文献   

3.
This work presents the synthesis, crystal structure and properties of a novel noncentrosymmetric (NCS) coordination polymer (CP), namely, (Me2NH2)3[BaLi(2,6‐PyDC)3(H2O)] ( 1 ) (2,6‐PyDC = pyridine‐2,6‐dicarboxylate acid), which represents the first example of BaLi‐CPs with 2,6‐PyDC ligand. Single‐crystal X‐ray structural analysis reveals that the compound features a two‐dimensional (2D) layered structure. The simplified structure of each layer belongs to the hcb topology. The second harmonic generation (SHG) response of 1 is about 0.5 times that of KH2PO4 (KDP) marker. What is more, 1 emits bright blue light upon the excitation of 365 nm UV light with the quantum yield (QY, Φ) of 1.63%. The successful construction of this compound convinces the feasibility of constructing NCS CPs via the combination of [BaL3] unit and Li(I) ion.  相似文献   

4.
In the title compound, 4‐amino‐3‐propynyl‐1‐(β‐d ‐ribofur­anosyl)‐1H‐pyrazolo[3,4‐d]pyrimidine methanol solvate, C13H15N5O4·CH3OH, the torsion angle of the N‐glycosylic bond is between anti and high‐anti [χ = −101.8 (5)°]. The ribofuranose moiety adopts the C3′‐endo (3T2) sugar conformation (N‐type) and the conformation at the exocyclic C—C bond is +sc (gauche, gauche). The propynyl group is out of the plane of the nucleobase and is bent. The compound forms a three‐dimensional network which is stabilized by several hydrogen bonds (O—H·O and O—H·N). The nucleobases are stacked head‐to‐tail. The methanol solvent mol­ecule forms hydrogen bonds with both the nucleobase and the sugar moiety.  相似文献   

5.
A series of open‐framework aluminoborates (ABOs), namely, [Zn2(en)5][Al2B10O20] ( 1 ), [Zn(en)(dien)][AlB5O10] ( 2 ), [Zn(en)3][AlB7O12 (OH)2] ( 3 ), [Zn(en)2][AlB5O10] ( 4 ), K7{AlO0.5[BO2(OH)]Zn@[B12O21(OH)3]}?H2O ( 5 ) (en=ethylenediamine, dien=diethylenetriamine) have been made under mild solvothermal conditions and characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction, elemental analysis, IR and UV/Vis spectroscopy, thermogravimetric analysis, and nonlinear optical determination. They were classified as two types: Compounds 1 – 4 contain intersecting channels and exhibit various 4‐connected nets built by AlO4 tetrahedra and oxo boron clusters, zinc–amine complexes act as the templates ( 1 – 3 ) or directly bond to the walls of the ABO ( 4 ); compound 5 exhibits a double‐layer structure made by nanosized [BO2(OH)]Zn@[B12O21(OH)3] ({BZn@B12}) clusters with Al2O7 dimers, the channels are within the layer. The second harmonic generation (SHG) measurement shows that the SHG responses of 1 – 3 are about 2.5, 1.6, and 0.5 times that of KH2PO4. Compounds 1 – 2 are type I phase‐matchable materials. UV/Vis spectroscopy indicates that compounds 1 – 5 are wide‐band‐gap semiconductors.  相似文献   

6.
A meticulously designed, polar, non‐centrosymmetric lead borate chloride, Pb2BO3Cl, was synthesized using KBe2BO3F2 (KBBF) as a model. Single‐crystal X‐ray diffraction revealed that the structure of Pb2BO3Cl consists of cationic [Pb2(BO3)]+ honeycomb layers and Cl? anions. Powder second harmonic generation (SHG) measurements on graded polycrystalline Pb2BO3Cl indicated that the title compound is phase‐matchable (type I) and exhibits a remarkably strong SHG response, which is approximately nine times stronger than that of potassium dihydrogen phosphate, and the largest efficiency observed in materials with structures similar to KBBF. Further characterization suggested that the compound melts congruently at high temperature and has a wide transparency window from the near‐UV to the mid‐IR region.  相似文献   

7.
Two tetranuclear compounds [Ln4Na(μ4‐OH)(TC4A)2(acac)4] [Ln = Tb ( 1 ), Eu ( 2 )] (acac = acetylacetonate) were synthesized and characterized based on ptert‐butylthiacalix[4]arene (H4TC4A). Compounds 1 and 2 are isostructural and crystallize in the monoclinic C2/c space group. There are two crystallographically independent metal atoms in one asymmetric unit. Ln1, Ln2, and two metal atoms generated by the symmetry operation are bridged by one μ4‐OH group to form a planar tetragonal Ln44‐OH) unit. Each Ln44‐OH) unit is surrounded by four acac anions and two disordered sodium ions in the planar direction. The upper and lower positions of the Ln44‐OH) unit are further coordinated by two cone‐shaped TC4A ligands to form a sandwich‐type molecular structure. Luminescent measurements reveal that both compounds 1 and 2 exhibit good photoluminescent properties. Moreover, the static and dynamic magnetic properties of compound 1 were also investigated, which demonstrates that 1 is one functional material candidate combining luminescent and antiferromagnetic properties in one molecule.  相似文献   

8.
The nonlinear optical property of new polyester has been studied via second harmonic generation (SHG). The values of electro‐optic coefficients, d33 and d31, of the poled polymer film were 3.15 × 10 ?7 and 1.5 × 10?7 esu, respectively. Thermal behavior of this polyester was studied through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). 4‐di‐(2′‐hydroxyethoxy)‐4‐diphenyl‐hydrazonomethyl was synthesized from the reaction of 3,4‐dihydroxy‐4‐diphenyl‐hydrazonomethyl with 2–chloro–1‐ethanol in a 1:2 mole ratio and subsequently reacted with terephthaloyl chloride (TPC) in the presence of pyridine, as catalyst, to produce the new nonlinear polyester. The chemical structures of the resulting monomers and polymer were characterized by CHN analysis, 1H‐NMR, FT‐IR, and UV–Vis spectroscopy. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

9.
The organic‐inorganic hybrid nonlinear optical (NLO) material NH4B(d‐ (+)‐C4H4O5)2 · H2O (NBC) was synthesized in a borate‐carboxylic acid system. Its structure was determined by single crystal X‐ray diffraction. It crystallizes in the orthorhombic system, space group Pna21 (No. 33), with cell parameters a = 11.484(6) Å, b = 5.354(3) Å, c = 21.079(12) Å, V = 1296.0(12), Z = 4. It exhibits a three‐dimensional pseudo tunnel structure consisting of fundamental building block [B(d‐ (+)‐C4H4O5)2] anions. The small cavities are occupied by the H2O molecules and NH4+ cations, which stabilize the whole structure by O–H ··· O and N–H ··· O hydrogen bonds. The powder X‐ray diffraction (PXRD) of the crystal was also recorded. Elemental analyses, FT‐IR and FT‐Raman spectra analyses, thermal analysis, and diffuse‐reflectance spectra for the compound are also presented, as are band structures and density of states calculation. Nonlinear optical measurements indicate that the material has second harmonic generation (SHG) properties and is phase‐matchable.  相似文献   

10.
Reaction between an aqueous ethanol solution of tin(II) chloride and that of 4‐propanoyl‐2,4‐dihydro‐5‐methyl‐2‐phenyl‐3 H‐pyrazol‐3‐one in the presence of O2 gave the compound cis‐dichlorobis(4‐propanoyl‐2,4‐dihydro‐5‐methyl‐2‐phenyl‐3 H‐pyrazol‐3‐onato) tin(IV) [(C26H26N4O4)SnCl2]. The compound has a six‐coordinated SnIV centre in a distorted octahedral configuration with two chloro ligands in cis position. The tin atom is also at a pseudo two‐fold axis of inversion for both the ligand anions and the two cis‐chloro ligands. The orange compound crystallizes in the triclinic space group P 1 with unit cell dimensions, a = 8.741(3) Å, b = 12.325(7) Å, c = 13.922(7) Å; α = 71.59(4), β = 79.39(3), γ = 75.18(4); Z = 2 and Dx = 1.575 g cm–3. The important bond distances in the chelate ring are Sn–O [2.041 to 2.103 Å], Sn–Cl [2.347 to 2.351 Å], C–O [1.261 to 1.289 Å] and C–C [1.401 Å] the bond angles are O–Sn–O 82.6 to 87.7° and Cl–Sn–Cl 97.59°. The UV, IR, 1H NMR and 119Sn Mössbauer spectral data of the compound are reported and discussed.  相似文献   

11.
This study aims to perform the chelation of difluoroboron (BF2) to quinacridonequinone (QQ). The resulting dark green solid was determined to be QA‐BF2, which is a BF2 complex of 6,13‐dihydroxyquinacridone (QA‐OH), and not QQ‐BF2, which is a BF2 complex of QQ. This result indicated that QQ‐BF2 was first generated as an O,O‐bidentate chelate, which immediately underwent a two‐electron reduction to produce QA‐BF2. This compound was converted to air‐sensitive QA‐OH by undergoing hydrolysis in argon. Since QA‐OH has a strong electron‐donating property, it easily produced QQ via air oxidation in the solution. QA‐OH also acts as a reducing reagent for quinones. The crystal packing of QA‐OH is a herringbone type with short π???π contacts, and a good hole mobility has been suggested by theoretical calculations. Herein, a new synthetic method from QQ to QA‐OH using BF2 chelation and hydrolysis was proposed. QA‐BF2 and QA‐OH are useful organic functional pigments and reducing reagents.  相似文献   

12.
The title compound, {[Zn4(C8H4O4)3(OH)2(C12H6N2O2)2]·2H2O}n, has been prepared hydrothermally by the reaction of Zn(NO3)2·6H2O with benzene‐1,4‐dicarboxylic acid (H2bdc) and 1,10‐phenanthroline‐5,6‐dione (pdon) in H2O. In the crystal structure, a tetranuclear Zn4(OH)2 fragment is located on a crystallographic inversion centre which relates two subunits, each containing a [ZnN2O4] octahedron and a [ZnO4] tetrahedron bridged by a μ3‐OH group. The pdon ligand chelates to zinc through its two N atoms to form part of the [ZnN2O4] octahedron. The two crystallographically independent bdc2− ligands are fully deprotonated and adopt μ3‐κOO′:κO′′ and μ4‐κOO′:κO′′:κO′′′ coordination modes, bridging three or four ZnII cations, respectively, from two Zn4(OH)2 units. The Zn4(OH)2 fragment connects six neighbouring tetranuclear units through four μ3‐bdc2− and two μ4‐bdc2− ligands, forming a three‐dimensional framework with uninodal 6‐connected α‐Po topology, in which the tetranuclear Zn4(OH)2 units are considered as 6‐connected nodes and the bdc2− ligands act as linkers. The uncoordinated water molecules are located on opposite sides of the Zn4(OH)2 unit and are connected to it through hydrogen‐bonding interactions involving hydroxide and carboxylate groups. The structure is further stabilized by extensive π–π interactions between the pdon and μ4‐bdc2− ligands.  相似文献   

13.
A 3D organic–inorganic hybrid compound, (2‐MepyH)3 [{Fe(1,10‐phen)3}3][{Pr4Sb12O18(OH) Cl11.5}(TDC)4.5({Pr4Sb12O18(OH)Cl9.5} Cl)] ? 3 (2‐Mepy) ? 28 H2O ( 1 ; 2‐Mepy=2‐methylpyridine, 1,10‐phen=1,10‐phenanthroline, H2TDC=thiophene‐2,5‐dicarboxylic acid), was hydrothermally synthesized and structurally characterized. Unusually, two kinds of high‐nuclearity clusters, namely [(Pr4Sb12O18 (OH)Cl11)(COO)5]5? and [(Pr4Sb12O18 (OH)Cl9)Cl(COO)5]4?, coexist in the structure of compound 1 ; two of the latter clusters are doubly bridged by two μ2‐Cl? moieties to form a new centrosymmetric dimeric cluster. An unprecedented spontaneous and reversible single‐crystal‐to‐single‐crystal transformation was observed, which simultaneously involved a notable organic‐ligand movement between the metal ions and an alteration of the bridging ion in the dimeric cluster, induced by guest‐release/re‐adsorption, thereby giving rise to the interconversion between compound 1 and the compound (2‐MepyH)3[{Fe(1,10‐phen)3}3][{Pr4Sb12O18(OH)Cl11.5}(TDC)4({Pr4Sb12O18Cl10.5(TDC)0.5(H2O)1.5}O0.5)] ? 25 H2O ( 1′ ). The mechanism of this transformation has also been discussed in great detail. Photocatalytic H2‐evolution activity was observed for compound 1′ under UV light with Pt as a co‐catalyst and MeOH as a sacrificial electron donor.  相似文献   

14.
We evaluated the individual atom contributions to the second harmonic generation (SHG) coefficients of LiCs2PO4 (LCPO) by introducing the partial response functionals on the basis of first principles calculations. The SHG response of LCPO is dominated by the metal‐cation‐centered groups CsO6 and LiO4, not by the nonmetal‐cation‐centered groups PO4 expected from the existing models and theories. The SHG coefficients of LCPO are determined mainly by the occupied orbitals O 2p and Cs 5p as well as by the unoccupied orbitals Cs 5d and Li 2p. For the SHG response of a material, the polarizable atomic orbitals of the occupied and the unoccupied states are both important.  相似文献   

15.
In the title compound, [Cu(C8H4O5)(C5H5N)2]n or [Cu(OH‐BDC)(py)2]n (where OH‐H2BDC is 5‐hydroxy­isophthalic acid and py is pyridine), the Cu atoms are coordinated by two N atoms from the pyridine ligands and by three O atoms from hydroxy­isophthalate ligands in a highly distorted triangular bipyramidal environment, with Cu—O distances in the range 1.941 (4)–2.225 (5) Å and Cu—N distances of 2.014 (6) and 2.046 (6) Å. The [Cu(OH‐BDC)]n two‐dimensional network is built up from interlocking 22‐, 15‐ and eight‐membered rings via sharing of Cu atoms and O—H⋯O hydrogen bonds. Consolidation of the packing structure is achieved by edge‐ or point‐to‐face C—H⋯π interactions and offset or slipped π–π stacking interactions.  相似文献   

16.
An ammonium‐containing metal iodate fluoride compound, (NH4)Bi2(IO3)2F5, featuring a two‐dimensional double‐layered framework constructed by [BiO2F5]6? and [BiO4F4]9? polyhedra, as well as [IO3]? groups, was successfully synthesized. The well‐ordered alignment of these SHG‐active units leads to an extraordinary strong SHG response of 9.2 times that of KDP. Moreover, this compound possesses a large birefringence (Δn=0.0690 at 589.3 nm), a wide energy band gap (Eg=3.88 eV), and a high laser damage threshold (LDT; 40.2×AgGaS2). In particular, thermochromic behavior was observed for the first time in this type of compound. Such multifunctional crystals will expand the application of nonlinear optical materials.  相似文献   

17.
r‐1, c‐2, t‐3, t‐4‐1,3‐Bis[2‐(5‐R‐benzoxazolyl)]‐2,4‐di(4‐R'‐phenyl)cyclobutane (IIa: R=R' = H; IIb: R=Me, R'= H; IIc: R = Me, R' = OMe) was synthesized with high stereo‐selectivity by the photodimerization of trans‐l‐[2‐(5‐R‐benzoxazolyl)]‐2‐(4‐R'‐phenyl) ethene (Ia: R=R' = H; Ib: R = Me, R' = H; Ic: R = Me, R' = OMe) in sulfuric acid. The structures of IIa–IIc were identified by elemental analysis, IR, UV, 1H NMR, 13C NMR and MS. The molecular and crystal structure of IIc has been determined by X‐ray diffraction method. The crystal of IIc (C34H30N2O4. 0.5C2OH) is monoclinic, space group P21/n with cell dimensions of a = 1.5416(3), b =0.5625(1), c = 1.7875(4) nm, β = 91.56 (3)°, V= 1.550(1) nm3, Z = 2. The structure shows that the molecule of IIc is centrosymmetric, which indicates that the dimerization process is a head‐to‐tail fashion. The selectivity of the photodimerization of Ia–Ic has been enhanced by using acidic solvent and the reaction speed would be decreased when electron donating group was introduced in the 4‐position of the phenyl group. That the photodimerization is not affected by the presence of oxygen as well as its high stereo‐selectivity demonstrated that the reaction proceeded through an excited singlet state. It was also found that under irradiation of short wavelength UV, these dimers underwent photolysis completely to reproduce its trans‐monomers, and then the new formed species changed into their cis‐isomers through trans‐cis isomerization.  相似文献   

18.
Achiral nonlinear optical (NLO) chromophores 1,3‐diazaazulene derivatives, 2‐(4′‐aminophenyl)‐6‐nitro‐1,3‐diazaazulene (APNA) and 2‐(4′‐N,N‐diphenylaminophenyl)‐6‐nitro‐1,3‐diazaazulene (DPAPNA), were synthesized with high yield. Despite the moderate static first hyperpolarizabilities (β0) for both APNA [(136 ± 5) × 10?30 esu] and DPAPNA [(263 ± 20) × 10?30 esu], only APNA crystal shows a powder efficiency of second harmonic generation (SHG) of 23 times that of urea. It is shown that the APNA crystallization driven cooperatively by the strong H‐bonding network and the dipolar electrostatic interactions falls into the noncentrosymmetric P212121 space group, and that the helical supramolecular assembly is solely responsible for the efficient SHG response. To the contrary, the DPAPNA crystal with centrosymmetric P‐1 space group is packed with antiparalleling dimmers, and is therefore completely SHG‐inactive. 1,3‐Diazaazulene derivatives are suggested to be potent building blocks for SHG‐active chiral crystals, which are advantageous in high thermal stability, excellent near‐infrared transparency and high degree of designing flexibility. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011  相似文献   

19.
Structures of cyclic 2‐(3‐oxo‐3‐phenylpropyl)‐substituted 1,3‐diketones 4a – c were determined by 17O‐NMR spectroscopy and X‐ray crystallography. In CDCl3 solution, compounds 4a – c form an eight‐membered‐ring with intramolecular H‐bonding between the enolic OH and the carbonyl O(11)‐atom of the phenylpropyl group, as demonstrated by increased shielding of specifically labeled 4a – c in the 17O‐NMR spectra (Δδ(17O(11))=36 ppm). In solid state, intermolecular H‐bonding was observed instead of intramolecular H‐bonding, as evidenced by the X‐ray crystal‐structure analysis of compound 4b . Crystals of compound 4b at 293 K are monoclinic with a=11.7927 (12) Å, b=13.6230 (14) Å, c=9.8900 (10) Å, β=107.192 (2)°, and the space group is P21/c with Z=4 (refinement to R=0.0557 on 2154 independent reflections).  相似文献   

20.
The title molecule, 3‐{[4‐(3‐methyl‐3‐phenyl‐cyclobutyl)‐thiazol‐2‐yl]‐hydrazono}‐1,3‐dihydro‐indol‐2‐one (C22H20N4O1S1), was prepared and characterized by 1H NMR, 13C NMR, IR, UV–visible, and single‐crystal X‐ray diffraction. The compound crystallizes in the monoclinic space group P21 with a = 8.3401(5), b = 5.6976(3), c = 20.8155(14) Å, and β = 95.144(5)°. Molecular geometry from X‐ray experiment and vibrational frequencies of the title compound in the ground state has been calculated using the Hartree–Fock with 6‐31G(d, p) and density functional method (B3LYP) with 6‐31G(d, p) and 6‐311G(d, p) basis sets, and compared with the experimental data. The calculated results show that optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies values show good agreement with experimental data. Density functional theory calculations of the title compound and thermodynamic properties were performed at B3LYP/6‐31G(d, p) level of theory. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012  相似文献   

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