A rate constant for CH2(3B1) + CH3

Triplet methylene, CH₂(³B₁), and methyl radicals were produced by flash photolysis of a mixture of ketene and azomethane. A computer fit of the product ratios, using the known rate constants for CH₂ + CH₂, and CH₃ + CH₃, requires a rate constant of 5.0 × 10^?11 cm³ molecule^?1s^?1 for the reaction CH₂ + CH₃ ? C₂H₄ + H.     

Inorganic Chemistry Concepts,Vol. 6. Inorganic Stereochemistry : by D.L. Kepert,Springer-Verlag,Berlin; 227 pages,DM 154

The paramagnetic compounds [Os₂(OCOR)₄Cl₂] (R = n-C₃H₇, C₂H₇, C₂H₅, CH₂Cl) have been synthesized by reaction of [Os(OCOCH₃)₂Cl]_n with the appropriate acids and the binuclear tetracarboxylate bridged structure confirmed by X-ray analysis for R = n-C₃H₇, (OsOs distance 2.301 Å, cf. the related [Os₂(hp)₄Cl₂](CH₃CN)₂; OsOs, 2.357 Å) (hp = 2-hydroxypyridine anion).     

Methylene radical reaction with cis-butene-2

A study of the pressure dependence of the C₅ products from the reaction of cis-butene-2 and methylene is reported. Methylene was produced by the photolysis of diazomethane with 4358 Å light at 23° or 56°, and by photolysis of ketene with 3200 Å radiation at 23° or 100°. The change with increasing pressure of the relative amounts of the characteristically “triplet products” (trans-1,2-dimethylcyclopropane, trans-pentene-2 (TP2), and 3-methylbutene-1 (3MB1)) and “singlet products” (cis-1,2-dimethylcyclopropane (CDMC) and cis-pentene-2 (CP2)) are discussed. The behavior is reminiscent of that found in ³CH₂-cis-butene-2 systems and can be interpreted in terms of the rapid rate of rearrangement of an initial triplet diradical product component, due to ³CH₂, relative to the slower rate and readier collisional stabilization of an initial vibrationally-excited dimethyl cyclopropane product component, due to ¹CH₂. Relative rates of reactions of ¹CH₂ with allylic CH:vinyl CH:C?C in the neat liquid were, for diazomethane, 1:1.1:7.2 and, for ketene, 1:1.2:6.7.     

Primary processes in the 147-nm photolysis of 1,1-dichloroethane

The room temperature photolysis of 1,1-dichloroethane at 147 nm in the pressure range of 1.34-196.2 torr is characterized almost entirely by the molecular elimination of HCl, Cl₂, and small quantities of H₂. Acetylene is also produced. While it is possible that the C₂H₂ arises, in part, from the decomposition of vibrationally excited ground states of C₂H₃Cl and/or C₂H₄, in this particlar case serious consideration has to be given to alternative explanations where the products of the primary processes are formed in electronically excited states. The ±, elimination of molecular chlorine is not inconsistent with an increased degree of Cl? Cl interaction predicted for a «Rydberg «state of 1,1-C₂H₄Cl₂. Varying small yields of CH₄ are observed in the presence and absence of NO. The effect of large pressures of CF₄ on the quantum yields of the major products is extremely small. The extinction coefficient for 1,1-C₂H₄Cl₂ at 147 nm and 296°K is 246 ± 29 cm^?1 ± atm^?1.     

Di‐μ‐chlorido‐bis[dichloridobis(methylamido‐κN)bis(methylamine‐κN)titanium(IV)]

The title compound, [Ti₂Cl₆(C₂H₆N)₂(C₂H₇N)₂], is a binuclear octahedral complex lying about an inversion centre. There are four different chloride environments, two terminal [Ti—Cl = 2.2847 (5) and 2.3371 (5) Å] and two bridging [Ti—Cl = 2.4414 (5) and 2.6759 (5) Å], with the Ti—Cl distances being strongly influenced by both the ligand trans to the chloride and whether or not the chloride anion is bridging between the two Ti^IV centres. The compound forms a two‐dimensional network in the solid state, with weak intermolecular C—H...Cl interactions giving rise to a planar network in the (10) plane.     

Tetrakis(chloromethyl)phosphonium chloride monohydrate

Tetrakis­(chloro­methyl)­phospho­nium chloride monohydrate, C₄H₈Cl₄P⁺·Cl^?·H₂O or P(CH₂Cl)₄⁺·Cl^?·H₂O, is the first crystal structure determination of a tetrakis­(halogeno­methyl)­phospho­nium compound to date. The only comparable structures known so far are of phospho­nium ions containing just one halogeno­methyl group. The solvent water mol­ecule interacts with the Cl^? anion via hydrogen bonds, with O?Cl distances of 3.230 (2) and 3.309 (2) Å. The structure also contains several C—H?Cl^? and C—H?O contacts, though with longer D?A distances [D?A 3.286 (3)–3.662 (2) Å] or bent D—H?A angles. For these reasons, the C—H?Cl^? and C—H?O interactions should not be considered as strong hydrogen bonds.     

1‐Carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium chloride 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate monohydrate: a crystal stabilized by imidazolium zwitterions

The title compound, C₆H₉N₂O₂⁺·Cl⁻·C₆H₈N₂O₂·H₂O, contains one 2‐(3‐methyl‐1H‐imidazol‐3‐ium‐1‐yl)acetate inner salt molecule, one 1‐carboxymethyl‐3‐methyl‐1H‐imidazol‐3‐ium cation, one chloride ion and one water molecule. In the extended structure, chloride anions and water molecules are linked via O—H...Cl hydrogen bonds, forming an infinite one‐dimensional chain. The chloride anions are also linked by two weak C—H...Cl interactions to neighbouring methylene groups and imidazole rings. Two imidazolium moieties form a homoconjugated cation through a strong and asymmetric O—H...O hydrogen bond of 2.472 (2) Å. The IR spectrum shows a continuous D‐type absorption in the region below 1300 cm⁻¹ and is different to that of 1‐carboxymethyl‐3‐methylimidazolium chloride [Xuan, Wang & Xue (2012). Spectrochim. Acta Part A, 96 , 436–443].     

THE REACTION OF METHYLENE WITH HYDROGEN

Abstract— An investigation has been made of the reaction between methylene, formed by the photolysis of ketene, and hydrogen. Ethane, ethylene and methane are the major hydrocarbon products, and it has been shown that the formation of these products may be adequately described by the sequence of processes
CH₂CO + hv → CH₂+ CO (1)
CH₂+ H₂→ CH₃+H (2)
2CH₃→ C₂H₆ (3)
CH₃+ H₂+ CH₄+ H (4)
CH₂+ CH₂CO → C₂H₄+ CO (7)
In particular, the relative rates of ethane and methane formation are consistent with the known rate constants for reactions (3) and (4), and it is not therefore necessary to postulate the participation of an 'insertion' process
CH₂+ H₂→ CH₄ (6) to account for the formation of methane.
Decrease of the energy possessed by the methylene, either by increase of the wavelength of ketene photolysis, or by increase of gas pressure, is shown to result in an increase in the reactivity of the methylene towards ketene relative to its reactivity towards hydrogen (i.e. the ratio k₂/k₂ increases).     

Molybdänhalogenidcluster mit sechs terminalen Alkoholatliganden: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH und (C18H36N2O6Na2)2[Mo6Cl8(OC6H5)6]

Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6CH₃OH and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] . The reaction of Na₂[Mo₆Cl₈(OCH₃)₆] and 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6 CH₃OH ( 1 ), which is converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo₆Cl₈ⁱ(OR^a)₆]^2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo₆Cl₈(OC₆H₅)₆]^2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.     

Chloroheptakis(dimethyl sulfoxide)­uranium(IV) trichloride

In the title complex, [UCl(C₂H₆OS)₇]Cl₃, the uranium metal center is coordinated in a distorted bicapped trigonal prism geometry by seven O atoms from di­methyl sulfoxide ligands and by a terminal chloride ligand. Charge balance is maintained by three outer‐sphere chloride ions per uranium(IV) metal center. Principle bond lengths include U—O 2.391 (2)–2.315 (2) Å, U—Cl 2.7207 (9) Å, and average S—O 1.540 (5) Å.     

Die Kristallstruktur des 1 : 1-Adduktes zwischen Antimontrichlorid und Diphenylammoniumchlorid,SbCl3 · (C6H5)2NH2+Cl−

The Crystal Structure of the 1:1 Addition Compound between Antimony Trichloride and Diphenylammonium Chloride, SbCl₃ · (C₆H₅)₂NH₂⁺Cl^? The 1:1 addition compound between antimony trichloride and diphenylammoniumchloride SbCl₃ · (C₆H₅)₂NH₂⁺Cl^? crystallizes in the monoclinic space group P2₁/n with a = 5.668(8), b = 20.480(12), c = 14.448(17) Å, β = 110.4(1)° and Z = 4 formula units. Chains of SbCl₃ molecules and anion cation chains are bridged by Cl ions and form square tubes. The coordination of the Sb atoms by Cl atoms by Cl atoms and Cl ions is distorted octahedral. Mean distances are Sb? Cl = 2.37 Å for Sb? Cl (3×), 3.09 Å for Sb…Cl^? (2×) and 3.42 Å for Sb…Cl (1×). The Sb…Cl^? contacts and hydrogen bonds NH…Cl^? at 3.15 Å generate tetrahedral coordination of the Cl ions.     

Mechanism and rate constants of the CH2 + CH2CO reactions in triplet and singlet states: A theoretical study

Ab initio and density functional CCSD(T)-F12/cc-pVQZ-f12//B2PLYPD3/6-311G** calculations have been performed to unravel the reaction mechanism of triplet and singlet methylene CH₂ with ketene CH₂CO. The computed potential energy diagrams and molecular properties have been then utilized in Rice–Ramsperger–Kassel–Marcus-Master Equation (RRKM-ME) calculations of the reaction rate constants and product branching ratios combined with the use of nonadiabatic transition state theory for spin-forbidden triplet-singlet isomerization. The results indicate that the most important channels of the reaction of ketene with triplet methylene lead to the formation of the HCCO + CH₃ and C₂H₄ + CO products, where the former channel is preferable at higher temperatures from 1000 K and above. In the C₂H₄ + CO product pair, the ethylene molecule can be formed either adiabatically in the triplet electronic state or via triplet-singlet intersystem crossing in the singlet electronic state occurring in the vicinity of the CH₂COCH₂ intermediate or along the pathway of CO elimination from the initial CH₂CH₂CO complex. The predominant products of the reaction of ketene with singlet methylene have been shown to be C₂H₄ + CO. The formation of these products mostly proceeds via a well-skipping mechanism but at high pressures may to some extent involve collisional stabilization of the CH₃CHCO and cyclic CH₂COCH₂ intermediates followed by their thermal unimolecular decomposition. The calculated rate constants at different pressures from 0.01 to 100 atm have been fitted by the modified Arrhenius expressions in the temperature range of 300–3000 K, which are proposed for kinetic modeling of ketene reactions in combustion. © 2018 Wiley Periodicals, Inc.     

Hexa­aqua­bis­(di­methyl sulfoxide)­yttrium(III) trichloride

The title compound, [Y(C₂H₆OS)₂(H₂O)₆]Cl₃, contains the cation [Y(H₂O)₆{(CH₃)₂SO}₂]³⁺ with a distorted square antiprismatic geometry of the eight coordinated O atoms. The six water mol­ecules are coordinated with an average Y—O distance of 2.38 (2) Å, ranging from 2.360 (3) to 2.404 (3) Å. Each water mol­ecule forms two hydrogen bonds to the chloride anions with O—Cl distances ranging from 3.068 (4) to 3.422 (4) Å. The two di­methyl­ sulfoxide ligands, situated in the cis position with the O—Y—O angle equal to 83.22 (11)°, have Y—O distances of 2.269 (3) and 2.278 (3) Å.     

Organische Phosphorverbindungen. XXVII Die direkte Synthese von Tetramethylphosphoniumhalogeniden

The reaction of methyl chloride and methyl bromide with white phosphorus is studied under a variety of conditions, and the conditions giving a high yield of tetramethylphosphonium chloride and bromide are established. Thermal decomposition of [(CH₃)₄P]+Cl^? gives (CH₃)₃P and CH₃Cl, and alkaline decomposition of [(C₄H₉)₃(C₁₂H₂₅)P]+Cl? gives C₄H₁₀ and (C₄H₉)₂(C₁₂H₂₅)P?O.     

Bis[μ‐P,P′‐methylenebis(diisopropyl phosphonate)‐κ3O,O′:O]bis[chlorolithium(I)]: a centrosymmetric dimer of lithium chloride with terminal chloride anions

The molecule of the title dimeric compound, [Li₂Cl₂(C₁₃­H₃₀O₆P₂)₂] or [LiCl{[(ⁱPrO)₂P(O)]₂CH₂}]₂, lies about an inversion center and features tetrahedrally coordinated Li atoms. The neutral ligands each chelate to one metal center and bridge to the other center through P=O units. Unusually for lithium chloride complexes, the Cl⁻ ions are in terminal rather than bridging positions. Principal dimensions include Li—O(four‐membered ring) = 1.959 (3) and 2.056 (3) Å, Li—O(phosphonate ring) = 1.929 (3) Å, and Li—Cl = 2.293 (3) Å.     

trans‐Aquachloro[(1R,4R,8S,11S)‐6,13‐diammonio‐6,13‐dimethyl‐1,4,8,11‐tetra­azacyclo­tetra­decane‐κ4N1,4,8,11]nickel(II) trichloride trihydrate

The title compound, [NiCl(C₁₂H₃₂N₆)(H₂O)]Cl₃·3H₂O, has the bis­(diamine)‐substituted cyclic tetra­amine in a planar coordination to triplet ground‐state Ni^II [average Ni—N = 2.068 (3) Å], with a chloride ion [Ni—Cl = 2.4520 (5) Å] and a water mol­ecule [Ni—O = 2.177 (2) Å] coordinated in the axial sites. The amine substituents are protonated and equatorially oriented. The amine groups, ammonium groups, water molecules and chloride ions are linked by an extensive hydrogen‐bonding network.     

Crystal and molecular structures of the complexes of cobalt dichloride with 1-isopropenylimidazole and 1-vinylimidazole

The crystal and molecular structures of bis(1-isopropenylimidazole)dichlorocobalt (C₁₂H₁₆Cl₂·N₄Co) [R 0.036 (R _W 0.089) for 3229 unique reflections with I > 2σ(I)] and tetra(1-vinylimidazole)dichlorocobalt (C₂₀H₂₄Cl₂N₈Co) [R 0.031 (R _W 0.072) for 1863 unique reflections with I > 2σ(I)] were determined. In these molecular complexes, the monodentate terminal 1-alkenylimidazole ligands coordinate to the metal via a “pyridine” nitrogen atom. In C₁₂H₁₆Cl₂N₄Co, the Co atom has a distorted tetrahedral 2N,2Cl coordination. The coordination polyhedron of cobalt in C₂₀H₂₄Cl₂N₈Co is a strongly elongated 4N,2Cl octahedron. The Co-N and Co-Cl bonds [Co-N 2.015(2) and 2.032(4) Å; Co-Cl 2.229(2) Å] in the tetrahedral complex C₁₂H₁₆Cl₂N₄Co are shorter than those in the octahedral complex C₂₀H₂₄Cl₂N₈Co [Co-N 2.134(2) and 2.157(2) Å; Co-Cl 2.518(1) Å]. In the structures of both complexes there are short contacts involving the Cl atoms.     

An FTIR study of the Cl atom-initiated oxidation of CH2Cl2 and CH3Cl

The Cl atom-initiated oxidation of CH₂Cl₂ and CH₃Cl was studied using the FTIR method in the photolysis of mixtures typically containing Cl₂ and the chlorinated methanes at 1 torr each in 700 torr air. The results obtained from product analysis were in general agreement with those reported by Sanhueza and Heicklen. The relative rate constant for the Cl atom reactions of CH₂Cl₂ and CH₃Cl was determined to be k(Cl +CH₃Cl)/k(Cl + CH₂Cl₂) = 1.31 ± 0.14 (2σ) at 298 ± 2 K.     

7‐Carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate at 100 K

Both 7‐carboxyl­ato‐8‐hydroxy‐2‐methyl­quinolinium monohydrate, C₁₁H₉NO₃·H₂O, (I), and 7‐carboxy‐8‐hydroxy‐2‐methyl­quinolinium chloride monohydrate, C₁₁H₁₀NO₃⁺·Cl⁻·H₂O, (II), crystallize in the centrosymmetric P space group. Both compounds display an intramolecular O—H⋯O hydrogen bond involving the hydroxy group; this hydrogen bond is stronger in (I) due to its zwitterionic character [O⋯O = 2.4449 (11) Å in (I) and 2.5881 (12) Å in (II)]. In both crystal structures, the HN⁺ group participates in the stabilization of the structure via intermolecular hydrogen bonds with water mol­ecules [N⋯O = 2.7450 (12) Å in (I) and 2.8025 (14) Å in (II)]. In compound (II), a hydrogen‐bond network connects the Cl⁻ anion to the carboxylic acid group [Cl⋯O = 2.9641 (11) Å] and to two water mol­ecules [Cl⋯O = 3.1485 (10) and 3.2744 (10) Å].     

4‐Amino‐N‐isopropyl­benzamidinium chloride ethanol solvate

The title compound, C₁₀H₁₆N·Cl⁻·C₂H₆O, is an important intermediate in the convergent synthesis of amidine‐substituted polycyclic heterocycles, a class of compounds that shows significant anticancer activity. The molecule of (I) is not planar, having a dihedral angle of 25.00 (7)° between the aniline and amidine (–C—NH=C=NH₂) groups. The proton­ation of the amidine molecular fragment is accompanied by delocalized C—N bond distances of 1.320 (2) and 1.317 (2) Å. The cations and chloride anions are involved in a network of hydrogen bonds, resulting in the formation of infinite chains propagating along the b direction. The chains are further grouped within the ab plane, in such a way that the structure is segregated into layers dominated by hydro­phobic interactions involving N‐isopropyl residues and layers dominated by N—H⋯Cl [N⋯Cl = 3.275 (2)–3.596 (2) Å], O—H⋯Cl [O⋯Cl = 3.229 (3) Å] and N—H⋯O [N⋯O = 2.965 (3) Å] hydrogen bonds.