Study of the sensor response of spun metal phthalocyanine films to volatile organic vapors using surface plasmon resonance

tIn this work, thin films of chloroaluminium phthalocyanine (ClAlPc), fluoroaluminium phthalocyanine(FAlPc) and fluorochromium phthalocyanine (FCrPc), which are insoluble in conventional solvents, weredeposited by spin coating of their solutions in trifluoroacetic acid. The sensing response of these filmsversus acetic acid, three alcohols (methanol, ethanol, butanol) and three amines (methylamine, dimethy-lamine, trimethylamine) have been investigated using surface plasmon resonance as the sensing method.It has been shown that the sensor response of the investigated films decreases in the following order:acetic acid > alcohols > amines. The optical changes as monitored by SPR method have been used in con-junction with Fick’s second law of diffusion to determine the diffusion coefficients of analyte vapor duringthe films’ swelling process. The obtained results showed that the diffusion coefficients and the swellingcharacteristics of the films are dependent on the functional group of the phthalocyanine molecule andthe molecular size of the analyte

Halochromic coordination polymers based on a triarylmethane dye for reversible detection of acids

Chromeazurol B (Na2HL) is a pH-sensitive (halochromic) dye based on a hydroxytriarylmethane core and two carboxylate functional groups, which makes it suitable for the synthesis of coordination polymers. Two new coordination polymers [NaZn4(H2O)3(L)3]·3THF·3H2O (1) and [Zn3(H2O)3(μ2- OH2)(μ3-OH)(HL)2(H2L)]·2THF·3H2O (2) incorporating Chromeazurol B linkers have been prepared and characterised. The structure of 1 comprises pentanuclear heterometallic {Zn4Na} nodes linked by six L3– anions to give a layered structure with a honeycomb topology. 2 crystallizes as a double-chain ribbon (ladder) structure with two types of metal node: a mononuclear Zn(II) cation and tetranuclear {Zn(II)}4 cluster. Chromeazurol B anions link each tetranuclear cluster to four individual Zn(II) cations and each Zn(II) cation with four tetranuclear clusters. Both compounds show pH-sensitivity in water solution which can be observed visually, giving the first example of a halochromic coordination polymer. The halochromic properties of 1 towards HCl vapors were systematically investigated. As-synthesized violet-grey 1 reversibly changes color from orange to pink in the presence of vapors of 2M and 7M HCl, respectively. The coordination of the Chromeazurol B anion at each color stage was examined by diffuse reflectance spectroscopy and FT-IR measurements. The remarkable stability of 1 to acid and the observed reversible and reproducible color changes provide a new design for multifunctional sensor materials

Crystal structure of (E)-3-(1-iodoethylidene)-2,3-dihydro-[1,4]thiazino- [2,3,4-ij]quinolin-4-ium triiodide, C13H11I4NS

C13H11I4NS, monoclinic, C2/c (no. 15), a = 29.508(1) Å, b = 8.3747(3) Å, c = 14.9533(5) Å, β = 105.945(4)°, V = 3553.1 Å3, Z = 8, Rgt(F) = 0.056, wRref(F2) = 0.0705, T = 120 K.We thank financial support from Spanish Ministerio de Economía y Competitividad (MAT2010-15094, FPUgrant AP2008-03942 to A.D.) and EDRF. This work was supported by the Russian Ministry for Education and Science.Peer reviewe

Crystal structure of 8,10-diiodo-3-(iodomethyl)-2,3-dihydro-[1,4]oxazino- [2,3,4-ij]quinolin-4-ium triiodide, [C12H9I3NO]·I3, C12H9I6NO

C12H9I6NO, monoclinic, P21/n (no. 14), a = 9.2855(2) Å, b = 17.1834(4) Å, c = 12.2416(3) Å, ( = 93.258(2)°, V = 1950.1 Å3, Z = 4, Rgt(F) = 0.0433, wRref(F2) = 0.0630, T = 120 K.We thank for financial support from the Spanish Ministerio de Economía y Competitividad under projects MAT2010-15094 and FEDER. A.D. also thanks to Spanish Ministerio de Educación, Cultura y Deporte for the FPU grant AP2008-03942. This work was supported by the Russian Foundation for Basic Research, grant 14-03-00961a.Peer reviewe

First-Principles Crystal Engineering Of Nonlinear Optical Materials. Ii. Effect Of Halogen Bonds On The Structure And Properties Of Triiodobenzenes

Recently, we proposed a computational design strategy for organic nonlinear optical materials, based on the global minimization of lattice energy to predict the crystal packing from the first principles. Here, we validate this strategy on triiodobenzenes, which include CH···I hydrogen and I···I halogen bonding as the structure-determining components of their intermolecular interactions. To refine the van der Waals (vdW) parameters for an I atom, the ab initio potential surfaces for the model dimers were calculated at the CCSD(T)/cc-pVTZ + CP theory level. The hydrogen bond C-H···I was found to have an interaction energy of -0.5 kcal/mol. The I···I contact of type I (140°-140°) was found to be attractive with a well depth of -0.4 kcal/mol at a 4.6 Å distance, whereas type II contact (180°-90°) was found to be nearly twice more attractive. Its potential well depth reaches -0.7 kcal/mol at an I···I distance of 4.4 Å. These binding energies are therefore weaker than that of the typical hydrogen bonds. The AMOEBA force-field vdW parameters were fit to describe these interactions and used to predict the crystal structures. Our structure prediction, followed by density functional theory - many-body dispersion ranking established the noncentrosymmetric crystal packing to be the global minimum, in agreement with the experimental data. The coupled perturbed Kohn-Sham approach was used to estimate nonlinear susceptibility, and the predicted values were compared to that of the urea standard. The statistical analysis of the angular distribution for the I···I contacts in the predicted virtual polymorphs was compared to that found among the experimental crystal structures of iodoaromatic compounds. In both cases, symmetric (type I) contacts dominate for shorter and longer I···I distances, whereas L-shaped (type II) contacts are preferred for intermediate distances

Toward First-Principles Design Of Organic Nonlinear Optical Materials: Crystal Structure Prediction And Halogen Bonding Impact On Hyperpolarizabilities Of 2-Iodo-3-Hydroxypyridine

Computational methods can potentially accelerate development of more efficient organic materials for second harmonic generation. Here, we test the method that includes the evolutionary algorithm for predicting crystal structure and prognosis of nonlinear optical properties based on the predicted structure. For this test, we selected 2-iodo-3-hydroxypyridine, which exhibits second harmonic generation intensity comparable to that of urea. We performed global minimization of the lattice energy and found the experimental structure when many-body dispersion correction is added to the density functional theory values. We analyzed geometric preferences of the halogen bonding in predicted virtual polymorphs. We also found linear correlation between the lengths of the iodine-iodine halogen bonds and calculated second order susceptibilities

Halogen Bonding and Other Iodine Interactions in Crystals of Dihydrothiazolo(oxazino)quinolinium Oligoiodides from the Electron-Density Viewpoint

The spatial organization of electron density in dihydrothiazolo­(oxazino)­quinolinium crystals with oligoiodide anions of various structures has been studied on the basis of 3D periodic Kohn–Sham calculations. The combination of QTAIMC and the analysis of one-electron potential and electrostatic potential has revealed the significant differences between halogen bonds (Type II interactions) and van der Waals (Type I) interactions for iodine atoms in crystalline environment. The traces of σ-holes in electrostatic potential on the zero-flux interatomic surfaces of iodine moieties are the distinctive feature of halogen bonding; they do not appear in the weak van der Waals I···I interactions at all. The analysis of superposition of the gradient fields of the electron density and electrostatic potential has allowed detection of the strong electron redistribution along the oligoiodide chain [I₃^–···II···I₃^–]; the electron density is shifted from I₃^– moiety to the cation via iodine molecule I₂ as a mediator. The quantitative relationship between the experimentally measured dissociation energy <i>D</i>_e(II/I···I) and the kinetic energy density at the bond critical point in the whole range of observed iodine interactions has been established

Synthesis, Properties and Aging of ICP-CVD SiCxNy:H Films Formed from Tetramethyldisilazane

Amorphous hydrogenated silicon carbonitride films were synthesized on Si(100), Ge(111), and fused silica substrates using the inductively coupled plasma chemical vapor deposition technique. 1,1,3,3-tetramethyldisilazane (TMDSN) was used as a single-source precursor. The effect of the precursor&rsquo;s pressure in the initial gas mixture, the substrate temperature, the plasma power, and the flow rate of nitrogen gas as an additional reagent on the film growth rate, element composition, chemical bonding, wettability of film surface, and the optical and mechanical properties of a-SiCxNy:H films was investigated. In situ diagnostic studies of the gas phase have been performed by optical emission spectroscopy during the film deposition process. The long-term stability of films was studied over a period of 375 days. Fourier-transform infrared (FTIR) and X-ray energy dispersive spectroscopy (EDX), and wettability measurements elucidated the oxidation of the SiCxNy:H films deposited using TMDSN + N2 mixture. Films obtained from a mixture with argon had high stability and maintained the stability of element composition after long-term storage in ambient air

CCDC 1504745: Experimental Crystal Structure Determination

Related Article: Marina S. Zavakhina, Irina V. Yushina, Denis G. Samsonenko, Danil N. Dybtsev, Vladimir P. Fedin, Stephen P. Argent, Alexander J. Blake, Martin Schröder|2017|Dalton Trans.|46|465|doi:10.1039/C6DT03969

CCDC 1504746: Experimental Crystal Structure Determination

Related Article: Marina S. Zavakhina, Irina V. Yushina, Denis G. Samsonenko, Danil N. Dybtsev, Vladimir P. Fedin, Stephen P. Argent, Alexander J. Blake, Martin Schröder|2017|Dalton Trans.|46|465|doi:10.1039/C6DT03969