High-resolution observation and analysis of the I(2) (+) A(2)Π(3∕2,u)-X (2)Π(3∕2,g) system

Rotationally resolved absorption spectra of I(2) (+) were recorded in 12 065-13 062 cm(-1) region by employing optical heterodyne velocity modulation absorption spectroscopy. In total, 4054 lines were assigned to 24 bands in the A(2)Π(3∕2,u)-X(2)Π(3∕2,g) system spanning the vibrational levels υ(') = 1-4 and υ(n) (') = 11-19. The assigned lines were globally fitted and an error of 0.003 cm(-1) was obtained. Rotational constants, B(υ), were used to derive equilibrium parameters B(e) (') = 0.03977725(77) cm(-1), a(e) (') = 1.1819(24)×10(-4) cm(-1), r(e) (') = 2.584386(25) A? of the X(2)Π(3∕2,g) state, and B(e) (') = 0.0305787(37) cm(-1), a(e) (') = 1.2353(23)×10(-4) cm(-1), r(e) (') = 2.94758(18) A? of the A(2)Π(3∕2,u) state. Vibrational energies were used to derive ω(e) (') = 239.0397(55) cm(-1), ω(e)x(e) (') = 0.64951(87) cm(-1) of the X(2)Π(3∕2,g) state and ω(e) (') = 138.103(11) cm(-1), ω(e)x(e) (') = 0.45027(34) cm(-1) of the A(2)Π(3∕2,u) state. The A(2)Π(3∕2,u) (υ(n) = 13) state was found to be rotationally perturbed by the a(4)Σ(1/2,u) (-) (υ(n) = 17) state through second-order spin-orbit coupling.     

Absolute radiolytic yields of N2(C3Πu) in N2/rare gas mixtures: Theoretical and experimental determinations

The absolute radiolytic luminescence yield for the emission from the C³Π_u state of N₂ has been determined for pulsed electron beam irradiation of He/N₂ and Ne/N₂ mixtures. The yields—corrected for all quenching processes—are compared to those calculated, by Monte-Carlo methods, from a model based on sub-excitation electron processes. The results confirm that this model and the Platzman initial sub-excitation electron distribution function are fully compatible with the observed results.The yields from experiment and theory are G(N₂, C³Π_u) = 0.079 ± 0.010 and 0.10 ± 0.01, respectively in He/N₂; 0.116 ± 0.037 and 0.094 ± 0.007 in Ne/N₂ mixtures.The G-values for absolute photon yields may be calculated from this data using appropriate kinetic quenching rate constants.     

State-to-state quantum dynamics of the N(4S) + OH(X2Π) → H(2S) + NO(X 2Π) reaction

Quantum state-to-state dynamics for the N((4)S) + OH(X(?2)Π) → H((2)S) + NO(X(?2)Π) reaction is reported on an accurate ab initio potential energy surface of the lowest triplet electronic state (a(3)A(")) of HNO∕HON. It was found that the reaction is dominated by long-lived resonances supported by the HNO and HON wells. Significant non-reactive scattering was observed, indicating substantial deviations from the statistical limit. Due to the large exothermicity of the reaction, the NO product has hot internal state distributions: its rotational state distribution is inverted and peaks near the highest accessible rotational level; and its vibrational state distribution extends to υ = 10 and decays monotonically with the vibrational quantum number. In particular, the predicted product vibrational distribution is in reasonably good agreement with experiment. The calculated differential cross section is dominated by scattering in both the forward and backward directions, consistent with the formation of reaction intermediates.     

N(4S)+ NO(X2Π)→N2(X3Σg-)+O(3P) 反应的立体动力学研究

采用准经典轨线方法研究了在不同碰撞能下，碰撞反应N(4S)+NO(X2Π)→ N2(X3Σg- )+O(3P)在两个最低势能面3A 和 3A'上产物与反应物之间的矢量相关. 结果表明，对于不同的碰撞能，在两个势能面上反应产物的转动取向展示了不同的特征和趋势. 随着碰撞能的增加，发生在3A 势能面上的反应主要受外平面机理支配，而发生在 3A' 势能面上的反应倾向于受内平面机理支配. 这些差异来自于两个势能面的不同构型.     

Polymeric (NO)3(N2O) n , (NO)3(N2O) n + , and (NO)3(N2O) n − : an interpretation of experimental observations

Semi-empirical and ab initio calculations are reported which provide a possible explanation for reported experimental results on 2-photon ionization of NO containing a few percent of N₂O, which found (NO)₃(N₂O) _n ^+or? clusters to be significantly more abundant than other (NO) _m (N₂O) _n products. It is found that the observed abundances of (NO)₃(N₂O) _n ionic clusters may be accounted for by the existence of covalent cyclic trimers of nitric oxide attached to oligomers of nitrous oxide. The extra stability of NO trimers in the observed clusters appears to arise from (NO) ₃ ⁺ rather than (NO)₃. Attachment of an (N₂O) _n side chain to (NO) ₃ ⁺ occurs exothermically. It is suggested that the addition of N₂O to cyclic-(NO) ₃ ⁺ might provide a means of making a polymer of nitrous oxide, which could have useful properties.     

Kinetics and Dynamics of the H(2S)+NO(X2Π)→N(4S)+OH(X2Π)Reaction:A Quasi-classical Trajectory Studyt

A quasi-classical trajectory study of the H(2S)+NO(X2Π)→N(4S)+OH(X2Π)reaction kinetics and dynamics is reported on an accu-rate potential energy surface.The tot...     

Reinvestigate the C2Π-X2Π(0,0) Band of AgO

The \begin{document}$ C^2\Pi $\end{document}-\begin{document}$ X^2\Pi $\end{document}(0, 0) band of AgO has been reinvestigated by laser induced fluorescence spectroscopy with a spectral resolution of \begin{document}$ \sim $\end{document}0.02 cm\begin{document}$ ^{-1} $\end{document}. The AgO molecules are produced by discharging a gas mixture of O\begin{document}$ _2 $\end{document}/Ar with silver needle electrodes in a supersonic jet expansion. By employing a home-made narrowband single longitude mode optical parametric oscillator (SLM-OPO) as the laser source, high-resolution spectra of the \begin{document}$ C^2\Pi $\end{document}-\begin{document}$ X^2\Pi $\end{document}(0, 0) band have been recorded for both \begin{document}$ ^{107} $\end{document}Ag\begin{document}$ ^{16} $\end{document}O and \begin{document}$ ^{109} $\end{document}Ag\begin{document}$ ^{16} $\end{document}O isotopologues. The spectroscopic constants of the \begin{document}$ C^2\Pi $\end{document} state are consequently determined, with the \begin{document}$ ^{109} $\end{document}Ag\begin{document}$ ^{16} $\end{document}O one being reported for the first time. The nature of the spin-orbit coupling effect in the \begin{document}$ C^2\Pi $\end{document} state is proposed to be due to state mixing with the nearby repulsive \begin{document}$ ^{4}\Sigma^{-} $\end{document} and \begin{document}$ ^{4}\Pi $\end{document} states.     

Binary group 15 polyazides. structural characterization of [Bi(N3)4]-, [Bi(N3)5]2-, [bipy·Bi(N3)5]2-, [Bi(N3)6]3-, bipy·As(N3)3, bipy·Sb(N3)3, and [(bipy)2·Bi(N3)3]2 and on the lone pair activation of valence electrons

The binary group 15 polyazides As(N(3))(3), Sb(N(3))(3), and Bi(N(3))(3) were stabilized by either anion or donor-acceptor adduct formation. Crystal structures are reported for [Bi(N(3))(4)](-), [Bi(N(3))(5)](2-), [bipy·Bi(N(3))(5)](2-), [Bi(N(3))(6)](3-), bipy·As(N(3))(3), bipy·Sb(N(3))(3), and [(bipy)(2)·Bi(N(3))(3)](2). The lone valence electron pair on the central atom of these pnictogen(+III) compounds can be either sterically active or inactive. The [Bi(N(3))(5)](2-) anion possesses a sterically active lone pair and a monomeric pseudo-octahedral structure with a coordination number of 6, whereas its 2,2'-bipyridine adduct exhibits a pseudo-monocapped trigonal prismatic structure with CN 7 and a sterically inactive lone pair. Because of the high oxidizing power of Bi(+V), reactions aimed at Bi(N(3))(5) and [Bi(N(3))(6)](-) resulted in the reduction to bismuth(+III) compounds by [N(3)](-). The powder X-ray diffraction pattern of Bi(N(3))(3) was recorded at 298 K and is distinct from that calculated for Sb(N(3))(3) from its single-crystal data at 223 K. The [(bipy)(2)·Bi(N(3))(3)](2) adduct is dimeric and derived from two BiN(8) square antiprisms sharing an edge consisting of two μ(1,1)-bridging N(3) ligands and with bismuth having CN 8 and a sterically inactive lone pair. The novel bipy·As(N(3))(3) and bipy·Sb(N(3))(3) adducts are monomeric and isostructural and contain a sterically active lone pair on their central atom and a CN of 6. A systematic quantum chemical analysis of the structures of these polyazides suggests that the M06-2X density functional is well suited for the prediction of the steric activity of lone pairs in main-group chemistry. Furthermore, it was found that the solid-state structures can strongly differ from those of the free gas-phase species or those in solutions and that lone pairs that are sterically inactive in a chemical surrounding can become activated in the free isolated species.     

Microwave spectroscopy of platinum monofluoride and platinum monochloride in the X 2Π(3/2) states

Platinum monofluoride (PtF) and platinum monochloride (PtCl) were detected in the gas phase using a source-modulated microwave spectrometer. The PtF and PtCl radicals were generated in a free space cell using the sputtering reaction from a platinum sheet placed on the inner surface of a stainless steel cathode through a dc glow discharge plasma of CF(4) and Cl(2), respectively, diluted with Ar. Rotational transitions were measured in the region between 150 and 313 GHz. Rotational, centrifugal distortion, and several fine- and hyperfine-structure constants were determined by a least-squares analysis. The observed fine-structure spectral patterns indicate that both PtF and PtCl radicals have the (2)Π(3/2) electronic ground states, while the related cyanide PtCN and hydride PtH radicals have the (2)Δ(5/2) electronic ground states.     

One-pot synthesis and fungicidal activity of 2-(1,5,3-dithiazepan-3-yl)ethanol and N,N′-bis(2-hydroxyethyl)tetrathiadiazacycloalkanes

Synthesis of 2-(1,5,3-dithiazepan-3-yl)ethanol and N,N′-bis(2-hydroxyethyl)tetrathiadiazacycloalkanes was performed by multicomponent condensation of monoethanolamine with formaldehyde and SH-acids (1,2-ethane, 1,3-propane-, 1,4-butane-, 1,5-pentane-, and 1,6-hexanedithiols). The resulting S,N-containing heterocycles and macrocycles possess fungicidal properties relative to microscopic fungi, plant pathogens.     

Chlorine reaction with platinum triamine [Pt(N,N-DimeTm)PyCl3]Cl (N,N-DimeTm = (CH3)2N(CH2)3NH2). Crystal structure of [Pt(N,N-DimeTm)Cl2], [Pt(N,N-DimeTm(Py)Cl3]Cl · H2O and [Pt{(CH3)2N(CH2)2C(O)NH}(Py)Cl3]

Treatment of platinum(II) diamine [Pt(N,N-DimeTm)Cl₂] (I) with pyridine gave tetramine [Pt(N,N-DimeTm)Py₂]Cl₂ (II); by oxidation with chlorine this was converted to Pt(IV) triamine, [Pt“(N,N-DimeTm(Py)Cl₃]Cl (III) with a six-membered chelate ring. According to X-ray diffraction data, the reaction of complex II with chlorine is accompanied by removal of the pyridine molecule from the trans-position to the NH₂ group of N,N-dimethyltrimethylenediamine. The reaction of complex III with chlorine at 20°C afforded a mixture of compounds (IV) and the complex [Pt“(CH₃)₂N(CH₂)₂C(O)NH”(Py)Cl₃] (V) with an amidate six-membered metal ring, dimethylpropioamide, which was also isolated upon refluxing a mixture of IV in an aqueous solution. The UV/Vis and IR spectra of the obtained complexes were studied, and X-ray diffraction analysis of I, III, and V was performed. The crystals of I are triclinic, space group P $ \bar 1 $ ; a = 7.6526(4) Å, b = 11.5571(6) Å, c = 12.4432(7) Å, α = 113.85(1)°, β = 96.54(2)°, γ = 106.78(2)°; Z = 4; R _hkl = 0.051. The crystals of III are monoclinic, space group C2/c; a = 36.715(2) Å, b = 7.8179(4) Å, c = 29.721(16) Å, β = 127.80(1)°; Z = 16; R _hkl = 0.036. The crystals of V are monoclinic, space group P2₁/n; a = 7.0398(6) Å, b = 27.458(2) Å, c = 7.687(6) Å, β = 106.270(1)°; Z = 4; R _hkl = 0.052.     

Experimental studies of the NaCs 5(3)Π0 and 1(a)3Σ+ states

We report high resolution measurements of 372 NaCs 5(3)Π(0)(v, J) ro-vibrational level energies in the range 0 ≤ v ≤ 22. The data have been used to construct NaCs 5(3)Π(0) potential energy curves using the Rydberg-Klein-Rees and inverted perturbation approximation methods. Bound-free 5(3)Π(0)(v, J) → 1(a)(3)Σ(+) emission has also been measured, and is used to determine the repulsive wall of the 1(a)(3)Σ(+) state and the 5(3)Π(0) → 1(a)(3)Σ(+) relative transition dipole moment function. Hyperfine structure in the 5(3)Π(0) state has not been observed in this experiment. This null result is explained using a simple vector coupling model.     

Investigation of Copper Halide:Hydrothermal Syntheses and Characterization of CuBr2(C12H8N2) and Cu3Br3(C12H8N2)2

The reaction of CuBr₂ with 1,10‐phen‐H₂O (1,10‐phen = 1,10‐phenanthroline) gave two compounds: CuBr₂(C₁₂H₈N₂) and Cu₃Br₃(C₁₂H₈N₂)₂. Their structures have been characterized by single‐crystal X‐ray diffraction analysis, elemental analyses, thermogravimetric analyses (TGA) and measurement of variable temperature magnetic susceptibility. Crystal data for CuBr₂(C₁₂‐H₈N₂): monoclinic, space group P2₁/n, a = 0.9977(3) nm, b = 0.65138(14) nm, c = 1.8207(4) nm, β = 91.624(18)°, V = 1.1828(5) nm³, Z = 2. Crystal data for Cu₃Br₃(C₁₂H₈N₂)₂: monoclinic, space group C2/c, a = 1.00167(11) nm, b = 1.4523(4) nm, c = 1.6295(3) nm, β = 94.386(14)°, V = 2.3635(8) nm³, Z = 3.     

Steric effect in the energy transfer reaction of oriented CO (a 3Π, v'=0, Ω=1 and 2) + NO (X 2Π) → NO (A 2Σ+, B 2Π) + CO (X 1Σ+)

The oriented CO (a (3)Π, v' = 0, Ω = 1 and 2) beam has been prepared by using an electric hexapole and applied to the energy transfer reaction of CO (a (3)Π, v' = 0, Ω = 1 and 2) + NO (X (2)Π) → NO (A (2)Σ(+), B (2)Π) + CO (X (1)Σ(+)). The emission spectra of NO (A (2)Σ(+), B(2)Π) have been measured at three orientation configurations (C-end, O-end, random). The shape of the emission spectra (and/or the internal excitation of products) turns out to be insensitive to the molecular orientation. The vibrational distributions of NO (A (2)Σ(+), v' = 0-2) and NO (B (2)Π, v' = 0-2) are determined to be N(v'=0):N(v'=1):N(v'=2) = 1:0.40 ± 0.05:0.10 ± 0.05 and N(v'=0):N(v'=1):N(v'= 2) = 1:0.6 ± 0.1:0.7 ± 0.1, respectively, and the branching ratio γ/β [=NO (A (2)Σ(+))/NO (B (2)Π)] is estimated to be γ/β ～ 0.3 ± 0.1 by means of spectral simulation. These vibrational distributions of NO (A, B) can be essentially attributed to the product-pair correlations between CO (X, v″) and NO (A (2)Σ(+), v' = 0-2), NO (B (2)Π, v' = 0-2) due to energetic restriction under the vibrational distribution of CO (X, v″) produced from the vertical transition of CO (a (3)Π, v' = 0) → CO (X, v″) in the course of energy transfer. The steric opacity function has been determined at two wavelength regions: 220 < λ < 290 nm [NO (A → X) is dominant]; 320 < λ < 400 nm [NO (B → X) is dominant]. For both channels NO (A (2)Σ(+), B(2)Π), a significant CO (a (3)Π) alignment effect is recognized; the largest reactivity at the sideways direction with the small reactivity at the molecular axis direction is observed. These CO (a (3)Π) alignment effects can be essentially attributed to the steric asymmetry on two sets of molecular orbital overlap, [CO (2π) + NO (6σ (2π))] and [CO (5σ) + NO (1π (2π))]. All experimental observations support the electron exchange mechanism that is operative through the formation of a weakly bound complex OCNO.     

Synthesis and crystal structures of N′-(3-ethoxy-2-hydroxybenzylidene)-3-methylbenzohydrazide and its dioxomolybdenum(VI) complex

A new hydrazone N′-(3-ethoxy-2-hydroxybenzylidene)-3-methylbenzohydrazide (H₂L), derived from condensation of 3-ethoxysalicylaldehyde with 3-methylbenzohydrazide, and its dioxomolybdenum(VI) complex [MoO₂L(CH₃OH)], have been prepared and characterized by physico-chemical methods and single crystal X-ray diffraction. The hydrazone coordinates to Mo through the phenolate O, imine N, and enolic O. The Mo is six-coordinate in a distorted octahedral geometry, with the three donors of L and one oxo defining the equatorial plane, and with one methanol and another oxo occupying the axial positions. The bond values especially for those related to the donors in the complex are different from those in H₂L.     

Synthesis and characterization by diffraction and 31P- and 77Se-NMR spectroscopy of [Mo3(μ3-Se)(μ2-Se2)3{N(SePPh2)2}3]Br and [Mo3(μ3-Se)(μ2-Se2)3{Se2P(OCH2CH3)2}3]Br

The new Mo/Se clusters [Mo₃(μ₃-Se)(μ₂-Se₂)₃{N(SePPh₂)₂}₃]Br (1) and [Mo₃(μ₃-Se)(μ₂-Se₂)₃{Se₂P(OCH₂CH₃)₂}₃]Br (2) have been synthesized by the selective substitution of the bromo ligands in the starting material [PPh₄]₂[Mo₃(μ₃-Se)(μ₂-Se₂)₃Br₆] with the selenoorgano bidentate ligands [N(SePPh₂)₂]^– and [Se₂P(OEt)₂]^–. The complexes have been characterized in solution by ³¹P- and ⁷⁷Se-NMR spectroscopy and in the solid state by single crystal X-ray diffraction; the same cation structures are present both in solution and in the solid state. Crystallographic data for 1: [Mo₃(μ₃-Se)(μ₂-Se₂)₃{N(SePPh₂)₂}₃]Br·3 CH₂Cl₂, C₇₂H₆₀BrMo₃N₃P₆Se₁₃·3 CH₂Cl₂, trigonal, space group R₃, a=21.299 (10) Å, c=38.433 (27) Å, V=15 100 (15) ų, T=−120 °C, Z=6; crystallographic data for 2: Mo₃(μ₃-Se)(μ₂-Se₂)₃{Se₂P(OCH₂CH₃)₂}₃]Br, C₁₂H₃₀BrMo₃P₃O₃Se₁₃, monoclinic, space group P2₁/n, a=13.404 (2) Å, b=22.732 (4) Å, c=13.932 (3) Å, β=113.134 (3)°, V=3 903.7(12) ų, T=−120 °C, Z=4. © 2000 Académie des sciences / Éditions scientifiques et médicales Elsevier SASphosphine ligands / amine ligands / phosphate ligands / selenium / molybdenum cluster / ⁷⁷Se-NMR spectroscopy     

Infrared investigations of the order–disorder ferroelectric phase transitions in imidazolium halogenobismuthates(III) and halogenoantimonates(III): (C3N2H5)5Bi2Cl11, (C3N2H5)5Bi2Br11 and (C3N2H5)5Sb2Br11

Infrared spectra of the powdered (C₃N₂H₅)₅Bi₂Cl₁₁, (C₃N₂H₅)₅Bi₂Br₁₁and (C₃N₂H₅)₅Sb₂Br₁₁ crystals in the region of internal vibrations of the imidazolium cations (3600 and 400 cm⁻¹) at the temperature intervals of 10–300 K, covering paraelectric–ferroelectric phase transitions, are presented and discussed in this paper. The research shows that the vibrational states of the imidazolium cations change markedly during the paraelectric–ferroelectric phase transition. The continuous nature of these transitions is well reflected in the infrared spectra, which is consistent with the previous X-ray and dielectric findings.     

Alignment effect of N2(A3Σu+) in the energy transfer reaction of aligned N2(A3Σu+) + NO(X2Π) → NO(A2Σ+) + N2(X1Σg+)

Steric effect in the energy transfer reaction of N(2)(A(3)Σ(u)(+)) + NO(X(2)Π) → NO(A(2)Σ(+)) + N(2)(X(1)Σ(g)(+)) has been studied under crossed beam conditions at a collision energy of ~0.07 eV by using an aligned N(2)(A(3)Σ(u)(+)) beam prepared by a magnetic hexapole. The emission intensity of NO(A(2)Σ(+)) has been measured as a function of the magnetic orientation field direction (i.e., alignment of N(2)(A(3)Σ(u)(+))) in the collision frame. A significant alignment effect on the energy transfer probability is observed. The shape of the steric opacity function turns out to be most reactive at the oblique configuration of N(2)(A(3)Σ(u)(+)) with an orientation angle of γ(v(R)) ~ 45° with respect to the relative velocity vector (v(R)), which has a good correlation with the spatial distribution of the 2pπ(g)* molecular orbital of N(2)(A(3)Σ(u)(+)). We propose the electron exchange mechanism in which the energy transfer probability is dominantly controlled by the orbital overlap between N(2)(2pπ(g)*) and NO(6σ).     

The 1(5)Π(g) state of C2

We report ab initio spectroscopic constants for the recently identified 1(5)Π(g) state of C(2) [P. Bornhauser, Y. Sych, G. Knopp, T. Gerber, and P. P. Radi, J. Chem. Phys. 134, 044302 (2011)]. The calculations are performed at the multi-reference configuration interaction level of theory with Davidson's correction using aug-cc-pV6Z basis sets and include core-valence correlation and relativistic corrections obtained with quadruple-zeta bases. Such treatment accurately reproduces the experimentally observed constants of the a(3)Π(u) and other states. Thus, we expect our calculated ω(e) value for the 1(5)Π(g) state to be within a few cm(-1), and rotational constants to be within 0.1% of experiment. Agreement with available spectroscopic data is excellent, with the calculations strongly suggesting that the 1(5)Π(g) vibrational level observed by Bornhauser et al. is v = 0.     

Structure and Spectroscopic Characteristics of N,N′-bis(2-Hydroxy-3-methoxyphenylmethylidene)2,6-pyridinediamine

The Schiff base N,N-bis(2-hydroxy-3-methoxyphenylmethylidene)-2,6-pyridinediamine has been synthesized and characterized in the solid state and in solution using X-ray analysis, IR, UV/Vis, and NMR spectroscopy. Crystal data: C₂₁H₁₉N₃O₄, M _r = 377.39, orthorhombic, space group Pnc2, a = 4.9288(8), b = 8.8873(19), c = 20.870(5) Å, V = 914.19(20) ų, Z = 2, R = 0.0387, R _w = 0.0530, 1845 independent reflections, 778 with I > 2(I). There are two intramolecular hydrogen bonds O—H-N between the hydroxyl and imino groups of 2.622(3) Å. The enolimine form is found in the solid state and is also the predominant tautomeric form in solution. Comparison of the title compound with the structurally related N,N-bis(salicylidene)-2,6-pyridinediamine and N,N-bis(salicylidene)-2,3-pyridinediamine is given.