Preliminary Results on Preparation and Performance of a Self-Emulsifying Waterborne Epoxy Curing Agent at Room Temperature.

Polyethylene glycol 1000 (PEG1000) and epoxy resin E20 were used to synthesize the E20/PEG1000 polymer (EP1K), which was later transformed into a self-emulsifying water-based epoxy curing agent by reacting with m-Xylylenediamine (MXDA). The effects of molecular weight, the molar ratio of the raw materials, the catalyst dosage, and the different co-solvents on the properties of the prepared curing agent were systematically explored. The infrared absorption spectra of E20, EP1K, and the water-based epoxy curing agent were compared and analyzed. The coating properties of the waterborne epoxy varnish, which was based on water-based epoxy curing agents to emulsify and cure the resin E44, were systematically tested. The results demonstrated that with a molar ratio of 1:1:4 of PEG1000, E20, and MXDA, the boron trifluoride etherate (BF3·Et2O) as catalyst accounts for 0.3% of the total mass of E20 and PEG1000, and an applicable period of 3 h for the prepared varnish, the anti-corrosion performance, and mechanical properties of the coatings were excellent.

Upcycling waste expanded polystyrene into UV-excited dual-mode multicolor luminescent electrospun fiber membranes for advanced anti-counterfeiting.

Expanded polystyrene (EPS) is causing severe environmental problems due to its high consumption and non-biodegradability. Upcycling waste EPS into high value-added functional materials is highly advisable in terms of sustainability and environmental concerns. Meanwhile, it is imperative to develop new anti-counterfeiting materials with high security against increasingly high-tech counterfeiting. Developing UV-excited dual-mode luminescent advanced anti-counterfeiting materials that can be excited by commonly used commercial UV light sources (such as 254 nm and 365 nm wavelengths) remains a challenge. Herein, UV-excited dual-mode multicolor luminescent electrospun fiber membranes were fabricated from waste EPS by co-doping with a Eu3+ complex and a Tb3+ complex via electrospinning. The SEM results prove that the lanthanide complexes are uniformly dispersed in the PS matrix. The luminescence analysis results suggest that all the as-prepared fiber membranes with the different mass ratios of the two complexes can exhibit the characteristic emission of Eu3+ ions and Tb3+ ions under UV light excitation. The corresponding fiber membrane samples can exhibit intense visible luminescence with different colors under UV lights. Moreover, each membrane sample can display different color luminescence irradiated with UV light at 254 nm and 365 nm, respectively, e.g. show excellent UV-excited dual-mode luminescent properties. This is owing to the different UV absorption properties of the two lanthanide complexes doped in the fiber membrane. Finally, the fiber membranes with different color luminescence from green light to red light were achieved by tuning the mass ratio of the two complexes in the PS matrix and changing UV irradiation wavelengths. The as-prepared fiber membranes with tunable multicolor luminescence are very promising for high-level anti-counterfeiting applications. This work is very meaningful not only to upcycle waste EPS to high value-added functional products but also to develop advanced anti-counterfeiting materials.

Synthesis of a Reactive Cationic/Nonionic Waterborne Polyurethane Dye Fixative and Its Application Performance on Viscose Fiber Fabrics.

A series of cationic waterborne polyurethane (CWPU) emulsions was synthesized with isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI) as hard segments; polyol (N210) and polyethylene glycol (PEG-2000) as soft segments; N-methyldiethanolamine (MDEA) as a hydrophilic chain extender; and trimethylolpropane (TMP) as a crosslinker. Then, the effects of the R-value, MDEA content, and TMP content on the properties of the CWPU emulsion, film, and fabric treatment were investigated. The results indicated that when the R-value was 3.0, the MEDA content accounted for 4.0% of the solid and the TMP content accounted for 1.0% of the solid. CWPU has excellent storage stability. Applying it to the fixing treatment of the viscose fiber fabrics can effectively improve the color fastness to rubbing, elasticity, surface smoothness, and anti-static properties.

Metalloporphyrin-based porous polymers prepared via click chemistry for size-selective adsorption of protein.

Zinc porphyrin-based porous polymers (PPs-Zn) with different pore sizes were prepared by controlling the reaction condition of click chemistry, and the protein adsorption in PPs-Zn and the catalytic activity of immobilized enzyme were investigated. PPs-Zn-1 with 18 nm and PPS-Zn-2 with 90 nm of pore size were characterized by FTIR, NMR and nitrogen absorption experiments. The amount of adsorbed protein in PPs-Zn-1 was more than that in PPs-Zn-2 for small size proteins, such as lysozyme, lipase and bovine serum albumin (BSA). And for large size proteins including myosin and human fibrinogen (HFg), the amount of adsorbed protein in PPs-Zn-1 was less than that in PPs-Zn-2. The result indicates that the protein adsorption is size-selective in PPs-Zn. Both the protein size and the pore size have a significant effect on the amount of adsorbed protein in the PPs-Zn. Lipase and lysozyme immobilized in PPs-Zn exhibited excellent reuse stability.

Carbon-Based Oxamate Cobalt(III) Complexes as Bioenzyme Mimics for Contaminant Elimination in High Backgrounds of Complicated Constituents.

Complex wastewater with massive components is now a serious environmental issue facing humanity. Selective removal of low-concentration contaminants in mixed constituents holds great promise for increasing water supplies. Bioenzymes like horseradish peroxidase exhibit oxidizing power and selectivity. Here, we manufactured its mimic through immobilizing non-heme oxamate anionic cobalt(III) complex ([CoIII(opba)]-, opba = o-phenylenebis(oxamate)) onto pyridine (Py) modified multiwalled carbon nanotubes ([CoIII(opba)]--Py-MWCNTs, MWCNTs = multiwalled carbon nanotubes), where MWCNTs captured substrates and Py functioned as the fifth ligand. We chose typical azo dye (C.I. Acid Red 1) and antibiotic (ciprofloxacin) as model substrates. Without •OH, this catalyst could detoxify target micropollutants efficiently at pH from 8 to 11. It also remained efficient in repetitive tests, and the final products were non-poisonous OH-containing acids. Combined with radical scavenger tests and electron paramagnetic resonance result, we speculated that high-valent cobalt-oxo active species and oxygen atom transfer reaction dominated in the reaction pathway. According to density functional theory calculations, the electron spin density distribution order showed that electron-withdrawing ligand was beneficial for inward pulling the excess electron and lowering the corresponding energy levels, achieving an electrophilic-attack enhancement of the catalyst. With target removal property and recyclability, this catalyst is prospective in water detoxication.

Structure and property investigations of TDO in aqueous phase by density functional theory, UV absorption, and Raman spectroscopy.

Density functional theory, UV absorption, and Raman spectroscopy are used to investigate the structure and properties of TDO in aqueous solution. The equilibrium structures, UV absorption spectra, interaction energies, and Raman spectroscopy data of TDO, AIMSA, and 12 TDO or AIMSA clusters are calculated. Raman spectroscopy experiments are carried out by 488 and 208 nm laser excitation. The Raman spectra of TDO in solid and aqueous phases have been compared, and the most possible structure for TDO in aqueous phase was deduced from analysis of the DFT calculations for the examined models, the experimental UV absorption spectrum, and Raman spectra of TDO. The interaction energy results show that TDO's solubility in water is originated from the TDO-water cyclic oligomer. The calculated UV absorption and Raman spectra of the I2·2H2O-cyc cluster model agree with the experimental results of TDO in aqueous solution very well.

Ordered-mesoporous-carbon-bonded cobalt phthalocyanine: a bioinspired catalytic system for controllable hydrogen peroxide activation.

The chemistry of enzymes presents a key to understanding the catalysis in the world. In the pursuit of controllable catalytic oxidation, researchers make extensive efforts to discover and develop functional materials that exhibit various properties intrinsic to enzymes. Here we describe a bioinspired catalytic system using ordered-mesoporous-carbon (OMC)-bonded cobalt tetraaminophthalocyanine (CoTAPc-OMC) as a catalyst that could mimic the space environment and reactive processes of metalloporphyrin-based heme enzymes and employing linear dodecylbenzenesulfonate as the fifth ligands to control the activation of H2O2 toward the peroxidase-like oxidation. The generation of nonselective free hydroxyl radicals was obviously inhibited. In addition, functional modification of OMC has been achieved by a moderate method, which can reduce excessive damage to the structure of OMC. Because of its favorable and tunable pore texture, CoTAPc-OMC provides a suitable interface and environment for the accessibility and oxidation of C.I. Acid Red 1, the model compound, and exhibits significantly enhanced catalytic activity and sufficient stability for H2O2 activation. The high-valent cobalt oxo intermediates with high oxidizing ability have been predicted as the acceptable active species, which have been corroborated by the results from the semiempirical quantum-chemical PM6 calculations.

Excited state structures and decay dynamics of 1,3-dimethyluracils in solutions: resonance Raman and quantum mechanical calculation study.

The resonance Raman spectroscopic study of the excited state structural dynamics of 1,3-dimethyluracil (DMU), 5-bromo-1,3-dimethyluracil (5BrDMU), uracil, and thymine in water and acetonitrile were reported. Density functional theory calculations were carried out to help elucidate the ultraviolet electronic transitions associated with the A-, and B-band absorptions and the vibrational assignments of the resonance Raman spectra. The effect of the methylation at N1, N3 and C5 sites of pyrimidine ring on the structural dynamics of uracils in different solvents were explored on the basis of the resonance Raman intensity patterns. The relative resonance Raman intensities of DMU and 5BrDMU are computed at the B3LYP-TD level. Huge discrepancies between the experimental resonance Raman intensities and the B3LYP-TD predicted ones were observed. The underlying mechanism was briefly discussed. The decay channel through the S1((1)nπ*)/S2((1)ππ*) conical intersection and the S1((1)nπ*)/T1((3)ππ*) intersystem crossing were revealed by using the CASSCF(8,7)/6-31G(d) level of theory calculations.

An in-source stretched membrane inlet for on-line analysis of VOCs in water with single photon ionization TOFMS.

An in-source, stretched, hollow fiber membrane (HFM) inlet has been developed to improve the sensitivity of on-line time-of-flight mass spectrometry (TOFMS) with a vacuum ultraviolet (VUV) lamp based single photon ionization (SPI) source for the direct analysis of liquid samples. A 2-cm HFM was stretched to 8 cm in length, and placed in the ion source and directly under the VUV lamp window with a distance of 15 mm. Compared with the conventional flow-through configuration under the same experimental conditions, the signal intensities of selected volatile organic compounds (VOCs) of methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), benzene, toluene and p-xylene were increased over 5-fold in magnitude, and the response time was shortened to one-third. The limits of detection (LOD) of MTBE, ETBE, benzene, toluene and p-xylene ranged from 0.25 to 1.3 µg L(-1) with a measurement time of 60 s, and three orders of linear range were obtained with correlation coefficients of 0.9972-0.9992. The present results suggest that the in-source stretched HFM is a simple and effective way to increase the sensitivity and shorten response time of the membrane inlet, and we believe that it will also be beneficial to other types of on-line mass spectrometer for the on-line analysis of VOCs in water with a VUV lamp based SPI ion source.

[Surface-enhanced raman scattering of thiabendazole adsorbed on silver nanoparticles].

In the present paper, quantum chemistry calculations method based on the density functional theory (DFT) and surface-enhanced Raman scattering (SERS) spectroscopy technique were used to investigate the adsorption behavior and enhancement effect of thiabendazole on the nanometer silver colloid surface systematically from theoretical and experimental perspective. By sodium citrate's reduction reaction, nanometer silver colloid with has high surface-enhanced Raman scattering activity was prepared. And then the authors studied the surface-enhanced Raman scattering spectroscopy of the thiabendazole in aqueous solution. The authors carried on the detailed quantum chemistry calculations for the interaction between thiabendazole and nanometer silver colloid, using the TBZ-Ag4 model to get the adsorption properties of thiabendazole molecule on nanometer silver colloid. Combining FT-Raman spectrum with the theoretical calculation results by the B3LYP/6-311G(d) theoretical level, and the visualization of GaussianView5. 0 software, the FT-Raman vibration spectrum and the surface-enhanced Raman scattering spectroscopy of thiabendazole molecule were assigned systematically. All the theoretical and experimental results show that all atoms of thiabendazole are in one plane and the point group of thiabendazole is Cs; Thiabendazole has high surface-enhanced Raman scattering activity on nanometer silver colloid surface; the thiabendazole is absorbed on silver colloid particles by S atom, and the long axis of thiabendazole molecule is perpendicular to the nanometer silver colloid surface; the trace concentration of thiabendazole can be detected rapidly and effectively with the surface-enhanced Raman scattering spectroscopy technique. This work provides a theoretical and experimental basis for the study of thiabendazole's characteristics and its rapid detection.

Excited-state structural dynamics of propanil in the S(2) state: resonance Raman and first-principle investigation.

Resonance Raman (RR) spectra and quantum chemical calculations were used to investigate the photodissociation dynamics of propanil in the S2 state. The RR spectra indicate that the photorelaxation dynamics for the S0 → S2 excited state of propanil is predominantly along nine motions: C═O stretch, ν51 (1659 cm(-1)), ring C═C stretch, ν50 (1590 cm(-1)), NH wag/ring C═C stretch, ν49 (1534 cm(-1)), ring CCH in-plane bend/NH wag, ν42 (1383 cm(-1)), NH wag/-CH2- rock, ν41 (1353 cm(-1)), ring C═C stretch/NH wag/-CH2- rock in-plane, ν40 (1299 cm(-1)), Ph-NH stretch/ring CCH in-plane bend, ν37 (1236 cm(-1)), ring CCH in-plane bend, ν35 (1150 cm(-1)), -CH2CH3 twist, ν33 (1080 cm(-1)), ring trigonal bend, ν31 (1029 cm(-1)), ring CCH bend out-of-plane, ν27 (899 cm(-1)), whole skeleton deformation in-plane, ν20(688 cm(-1)). Strong electron coupling between S1 and S2 of propanil is found by quantum chemistry calculations and depolarization spectra. The excited-state dynamics of the S2 state is discussed, and the results are compared with the previously reported results for formanilide to examine the Cl substitution effect.

Resonance Raman and density functional study of the excited state structural dynamics of 3-amino-2-cyclohexen-1-one in water and acetonitrile solvents.

FT-Raman and/or FT-IR spectra of 3-amino-2-cyclohexen-1-one (ACyO) in solid state and/or in solvents of water and acetonitrile were obtained. Density functional theory calculations were done to help elucidate the vibrational band assignments. The A-band resonance Raman spectra of ACyO were acquired in water and acetonitrile solvents to examine the excited state structural dynamics and the state-mixing or curve-crossing tuned by solvents. A preliminary resonance Raman intensity analysis using the time-dependent wave-packet theory and simple model was done for ACyO in acetonitrile solvent. Resonance Raman spectroscopic probing of the excited state curve-crossing or state-mixing was proposed.

Resonance Raman intensity analysis of the A band short-time photochemical dynamics of 4,5-ethylenedithio-1,3-dithiole-2-thione.

Resonance Raman spectra (RRs) for 4,5-ethylenedithio-1,3-dithiole-2-thione (EDDT) were obtained with 397.9 and 416 nm excitation wavelengths, and density functional calculations were performed to elucidate the electronic transitions and the RRs of EDDT in chloroform solvent. The RRs indicate that the Franck-Condon region photodynamics have multidimensional character with nuclear motion predominantly along the C(4)═C(5) stretch and the C(4)═C(5) twist out-of-plane. Resonance Raman cross-sections of A-band absorption have been obtained for the vibrational modes of EDDT with its excitation frequencies spanning the 408 nm. Resonance Raman intensity analysis of the resulting RRs excitation profiles and absorption spectrum using a time-dependent wave packet formalism yields mode-specific nuclear displacement and vibrational reorganizational energies. The intensity analysis results for EDDT were compared to previously reported results for dimethyl 1,3-dithiole-2-thione-4,5-dicarboxylate (DDTD), which shows that the additional six-member heterocycle of EDDT strongly affects the reorganizational energy and energy participation. The authors briefly discuss the differences and similarities of the spectra in terms of molecular symmetry and electron density.

Resonance Raman spectroscopic and theoretical investigation of the excited state proton transfer reaction dynamics of 2-thiopyridone.

The resonance Raman spectra were obtained for both 2-thiopyridone (2TP) and its proton-transfer tautomer 2-mercaptopyridine (2MP) in water solution. Density functional theory (DFT) calculations were carried out to help elucidate their ultraviolet electronic transitions and vibrational assignments of the resonance Raman spectra associated with their B-band absorptions. The nanosecond time-resolved resonance Raman spectroscopic experiment was carried out to further confirm the assignment that the transient species was the ground state 2MP. The different short-time structural dynamics were examined for both 2TP and 2MP in terms of their resonance Raman intensity patterns. The transition barriers between 2TP and 2MP for S(0), T(1), and S(1) states are determined by using (U)B3LYP-TD and CASSCF level of theory computations, respectively. The excited state proton transfer (ESPT) reaction mechanism is proposed and briefly discussed.

Resonance Raman and theoretical investigation of the photodissociation dynamics of benzamide in S3 state.

Resonance Raman spectra were obtained for benzamide in methanol and acetonitrile solutions with excitation wavelengths in resonance with the S(3) state. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with the motions mainly along the benzene ring C[Double Bond]C stretch nu(9), the Ph-CO-NH(2) and ring benzene stretch nu(14), the CCH in plane bend nu(17), the Ph-CO-NH(2) stretch and NH(2) rock nu(19), the ring trigonal bend nu(23), and the ring deformation and Ph-CO-NH(2) stretch nu(29). A preliminary resonance Raman intensity analysis was done, and the results were compared to those previously reported for acetophenone to examine the substituent effect. Solvent effect on the short-time photodissociation dynamics of benzamide was also examined. A conical intersection point S(2)S(3) between S(3) and S(2) potential energy surfaces of benzamide was determined by using a complete active space self-consistent field theory computations. The structural differences and similarities between S(3)S(2) point and S(0) were examined, and the results were used to correlate to the Franck-Condon photodissociation dynamics of benzamide in S(3) state.

Resonance Raman intensity analysis of the excited-state proton-transfer dynamics of 2-hydroxybenzaldehyde in the charge-transfer/proton-transfer absorption band.

Resonance Raman spectra were obtained for 2-hydroxybenzaldehyde (OHBA) in cyclohexane solution with excitation wavelengths in resonance with the first charge-transfer/proton-transfer (CT/PT) band absorption. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion predominantly along the nominal C=CH in-plane bend+ring deformation modes (nu9, nu10, nu14, nu16, nu18, nu19, nu20, nu26, nu30, nu31, and nu35) accompanied by a smaller amount of motion along the nominal C=O stretch mode (nu7), the nominal C=C-C(=O) in-plane bend modes (nu33 and nu37), and the nominal ring C-O-H in-plane bend modes (nu9 and nu14). A preliminary resonance Raman intensity analysis was done, and these results for the OHBA molecule were compared to results previously reported for the 2-hydroxyacetophenone (OHAP) molecule. Several proton-transfer tautomers in the ground and excited states were predicted from the results of B3LYP/cc-PVTZ, UB3LYP/cc-PVTZ, and CASSCF/cc-PVDZ level of theory computations. The differences and similarities between the CT/PT band resonance Raman spectra and the vibrational reorganizational energies for the OHBA molecule relative to those for the OHAP molecule are briefly discussed.

Resonance Raman and density functional theory investigation of the photodissociation dynamics of the A-band absorption of (E)-beta-nitrostyrene in cyclohexane solution.

Resonance Raman spectra were obtained for (E)-beta-nitrostyrene in cyclohexane solution with excitation wavelengths in resonance with the charge transfer (CT)-band absorption spectrum. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion predominantly along the nominal NO(2) symmetric stretch mode (nu(14)), the nominal C=C stretch mode (nu(8)), the nominal benzene ring stretch mode (nu(9)), accompanied by a smaller amount of motion along the nominal ONO symmetric bend/benzene ring stretch mode (nu(34)), the nominal CCH in-plane bending mode (nu(20)), the nominal HC=CH in-plane bending mode (nu(18)), the nominal NO(2) asymmetric stretch mode (nu(11)), the nominal C-N stretch/benzene ring breathing mode (nu(27)), and the nominal CCC trigonal bending mode (nu(25)). A preliminary resonance Raman intensity analysis was done and these results for (E)-beta-nitrostyrene were compared to results previously reported for several nitrobenzene and trans-stilbene compounds. The differences and similarities between the CT-band resonance Raman spectra and vibrational reorganizational energies for (E)-beta-nitrostyrene relative to those for nitrobenzene and trans-stilbene were briefly discussed.

Genome-wide analysis of the auxin response factors (ARF) gene family in rice (Oryza sativa).

Auxin response factors (ARFs) are transcription factors that bind with specificity to TGTCTC-containing auxin response elements (AuxREs) found in promoters of primary/early auxin response genes and mediate responses to the plant hormone auxin. The ARF genes are represented by a large multigene family in plants. A comprehensive genome-wide analysis was carried out in this study to find all ARFs in Arabidopsis (Arabidopsis thaliana) and rice (Oryza sativa subsp. japonica), 23 and 25 ARF genes, named as AtARFs and OsARFs, were identified, respectively. Chromosomal locations of all OsARFs were presented and it was found that the duplication of OsARFs was associated with only the chromosomal block duplications but not local tandem duplications. A phylogenetic tree was generated from alignments of the full-length protein sequences of 25 OsARFs and 23 AtARFs to examine the phylogenetic relationships of rice and Arabidopsis ARF proteins. All 48 members of ARF gene families fell into three major classes, a total of 13 sister pairs, including 9 OsARF-OsARF, 2 AtARF-AtARF and 2 AtARF-OsARF sister pairs were formed, showing different orthologous relationships between AtARFs and OsARFs. EST analysis and RT-PCR assays demonstrated that 24 of all 25 OsARF genes were active and the transcript abundance of some OsARF genes was affected by auxin treatment or light- and dark-grown conditions. The outcome of the present study provides basic genomic information for the rice ARF gene family and will pave the way for elucidating the precise role of OsARFs in plant growth and development in the future.

Resonance Raman intensity analysis of the excited state proton transfer dynamics of 2-nitrophenol in the charge-transfer band absorption.

Resonance Raman spectra were obtained for 2-nitrophenol in cyclohexane solution with excitation wavelengths in resonance with the charge-transfer (CT) proton transfer band absorption. These spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion along more than 15 normal modes: the nominal CCH bend+CC stretch nu(12) (1326 cm(-1)), the nominal CCC bend nu(23) (564 cm(-1)), the nominal CO stretch+NO stretch+CC stretch nu(14) (1250 cm(-1)), the nominal CCH bend+CC stretch+COH bend nu(15) (1190 cm(-1)); the nominal CCH bend+CC stretch nu(17) (1134 cm(-1)), the nominal CCC bend+CC stretch nu(22) (669 cm(-1)), the nominal CCN bend nu(27) (290 cm(-1)), the nominal NO(2) bend+CC stretch nu(21) (820 cm(-1)), the nominal CCO bend+CNO bend nu(25) (428 cm(-1)), the nominal CC stretch nu(7) (1590 cm(-1)), the nominal NO stretch nu(8) (1538 cm(-1)), the nominal CCC bend+NO(2) bend nu(20) (870 cm(-1)), the nominal CC stretch nu(6) (1617 cm(-1)), the nominal COH bend+CC stretch nu(11) (1382 cm(-1)), nominal CCH bend+CC stretch nu(9) (1472 cm(-1)). A preliminary resonance Raman intensity analysis was done and the results for 2-nitrophenol were compared to previously reported results for nitrobenzene, p-nitroaniline, and 2-hydroxyacetophenone. The authors briefly discuss the differences and similarities in the CT-band absorption excitation of 2-nitrophenol relative to those of nitrobenzene, p-nitroaniline, and 2-hydroxyacetophenone.

Ab initio and kinetic calculations for the reactions of Cl with SiH(n)Cl(4-n) (n=1,2,3,4).

The direct hydrogen abstraction reactions of Cl atom with SiH(n)Cl(4-n) (n=1,2,3,4) have been studied systematically using ab initio molecular orbital theory. Geometries have been optimized at the MP2 level with 6-311+G(d) basis set, QCISD(T)/6-311+G(d,p) has been used in the final single point energy calculation. The kinetic calculations of these reactions have been explored using the canonical variational transition (CVT) state theory method with small-curvature tunneling (SCT) effect correction over the temperature range of 200-2000 K. The CVT/SCT rate constants exhibit typical non-Arrhenius behavior and three-parameter rate-temperature formulas have been fitted for the reactions of Cl with SiH4, SiH3Cl, SiH2Cl2, and SiHCl3, respectively (in unit of cm(3) molecule(-1) s(-1)). The calculated CVT/SCT rate constants are in agreement with the available experimental values.