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1.
The mechanisms of SO2 oxidation catalyzed by iron ions in the droplet phase of the convective cloud in the lower atmosphere were examined. The relations of the catalytic SO2 decrease to the concentration of the iron ions and to the intensity of fluxes to the droplet of the OH
(g) and HO
2(g) radicals were characterized. The determining role of the replacement of the low-reactive HO
2(g)(O–
2(aq)) radical by the reactive SO–
5(aq) radical in the sulfite medium during daytime was revealed. This process occurred due to the coupling of the decay of the radicals and their regeneration in the liquid-phase reactions O–
2(aq) + FeOH2+
(aq) Fe2+
(aq) + OH–
(aq) + O2(aq), HSO–
5(aq) + Fe2+
(aq) FeOH2+
(aq) + SO–
4(aq)HSO
3
-
(aq),O2
(aq) SO–
5(aq). 相似文献
2.
Leticia Naya Margarita López-Torres José M. Vila Nina Gómez-Blanco 《Journal of organometallic chemistry》2008,693(4):685-700
Reaction of Pd(AcO)2 with the Schiff base ligands 2-Br-4,5-(OCH2O)C6H2C(H)N(Cy) (a) and 4,5-(OCH2CH2)C6H3C(H)N(Cy) (b) leads to the cyclometallated compounds [Pd{2-Br-4,5-(OCH2O)C6HC(H)N(Cy)-C6,N}(μ-O2CMe)]2 (1a) and [Pd{4,5-(OCH2CH2)C6H2C(H)N(Cy)-C6,N}(μ-O2CMe)]2 (1b), respectively, via C-H activation. Treatment of a with Pd2(dba)3 gave [Pd{4,5-(OCH2O)C6H2C(H)N(Cy)-C2,N}(μ-Br)]2 (6a), via C-Br activation. The metathesis reaction of 1a and 1b with aqueous sodium chloride gave the corresponding cyclopalladated dimers with bridging chloride ligands, 2a and 2b, respectively. Treatment of the halogen-bridged compounds with tertiary tri- and diphosphines in the appropriate molar ratio gave the mono and dinuclear compounds 3a-5a, 7a-9a and 3b-5b. The structure of compounds 3a, 4a, 5a, 8a, 2b, 3b and 5b has been determined by X-ray diffraction analysis. 相似文献
3.
The new ferrole Fe2(CO)6[μ-η2,η4-(Fc)CC{C(H)C(R)S}CC(SiMe3)] [R = SiMe3 (1) and R = Fc (2)] and ruthenoles Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(H)}CC(Fc)] 3 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC(SCCFc)C(H)C(Fc)] 4, have been obtained from the reactions of M3(CO)12 (M = Fe, Ru) and FcCCSCCSiMe3 through S-C bond activations and C-C coupling reactions. Thermolysis of Ru2(CO)6[μ3-η2,η4,η3-(Me3Si)CC{SC(Fc)C(SCCSiMe3}Ru(CO)3}CC(Fc)] alone and in the presence of HCCFc, yielded the compounds Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)}CC(Fc)] 5 and Ru2(CO)6[μ-η2,η4-(Me3Si)CC{SC(Fc)C(SCCSiMe3)C(H)C(Fc)}CC(Fc)] 6, respectively. The crystal structures of the compounds 1, 3, 4 and 6 are reported. 相似文献
4.
Javier Martínez José M. Antelo Ma Teresa Pereira José M. Vila 《Journal of organometallic chemistry》2006,691(13):2891-2901
Treatment of the thiosemicarbazones 4-FC6H4C(Me)NN(H)C(S)NHR, (R = Me, a; Ph, b) and 2-ClC6H4C(Me)NN(H)C(S)NHR (R = Ph, c) with lithium tetrachloropalladate(II) in methanol or palladium(II) acetate in acetic acid gave the tetranuclear cyclometallated complex [Pd{4-FC6H3C(Me)NNC(S)NHR}]4 (1a, 1b) and [Pd{2-ClC6H3C(Me)NNC(S)NHPh}]4 (1c). Reaction of these tetramers with the diphosphines dppe, t-dppe, dppp or dppb in a 1:2 molar ratio gave the dinuclear cyclometallated complexes [(Pd{4-FC6H3C(Me)NNC(S)NHR})2(μ-Ph2P(CH2)nPPh2)], (n = 2, 2a, 2b; 3, 4a, 4b; 4, 5a, 5b), [(Pd{4-FC6H3C(Me)NNC(S)NHPh})2(μ-Ph2PCHCHPPh2)], (3a, 3b) and [(Pd{2-ClC6H3C(Me)NNC(S)NHR})2(μ-Ph2P(CH2)nPPh2)], (n = 2, 2c, 2d; 3, 4c, 4d; 4, 5c, 5d), [(Pd{2-ClC6H3C(Me)NNC(S)NHPh})2(μ-PPh2CHCHPPh2)], (3c, 3d). The X-ray crystal structure of the ligand b and the complexes 3c, 4a and 4d were determined. The structures of complexes 4a and 4d show that the different disposition of the chain cyclometallated of the thiosemicarbazones (in the same orientation or in the opposite one) is due to the different H bonds produced. 相似文献
5.
6.
C. Balarew D. Rabadjieva S. Tepavitcharova C. Christov O. Angelova 《Journal of solution chemistry》1999,28(7):949-958
Crystallization of 2RbBr · MnBr2 · 2H2O, the only double salt obtained under standard conditions from saturated aqueous rubidium–manganese bromide solutions, was theoretically predicted using the hard and soft Lewis acids and bases concept and Pauling's rules. The RbBr—MnBr2—H2O system was thermodynamically simulated by the Pitzer model assuming a solubility diagram of three branches only: RbBr, 2RbBr · MnBr2 · 2H2O and MnBr2 · 4H2O. The theoretical result was experimentally proved at 25°C by the physicochemical analysis method and formation of the new double salt 2RbBr · MnBr2 · 2H2O was established. It was found to crystallize in a triclinic crystal system, space group –P1, a = 5.890(1) Å, b = 6.885(1) Å, c = 7.367(2) Å, = 66.01(1)°, = 87.78(2)°, = 84.93(2)°, V = 271.8(1) Å3, Z = 1, D
x = 3.552 g-cm–3. The binary and ternary ion interaction parameters were calculated and the solubility isotherm was plotted. The standard molar Gibbs energy of the synthesis reaction, rG
m
o
, of the double salt 2RbBr · MnBr2 · 2H2O from the corresponding simple salts RbBr and MnBr2 · 4H2O, as well as the standard molar Gibbs energy of formation, fG
m
o
, and standard molar enthalpy of formation fH
m
o
of the simple and double salts were calculated. 相似文献
7.
The compound (n-Bu4N)2[Re4Cl8(-Cl)2(-O)2 · 2THF] has been prepared from (n-Bu4N)2 Re2Cl8 by refluxing it in wet trifluoroacetic acid. It forms brown, block-shaped crystals in space group P
, withZ = 2 in a cell of dimensions:a = 11.748(1) Å,b = 16.847(3) Å,c = 16.953(3) Å, = 97.53(1)° = 106.49(1)° = 101.25(1)°V = 3093(1) Å3. There are two independent but practically identical tetranuclear anions, each on a crystallographic inversion center. The short, unbridged Re-Re edges, to which triple bonds are assigned have lengths of 2.280(1) Å and 2.276(1) Å and the longer edges, each with a -Cl and a -O atom have lengths of 2.611(1) Å and 2.615(1) Å, for molecules 1 and 2 respectively. This anion completes a series going from [Re4Cl8(-O)2(-OMe)2]2– through [Re4Cl8(-O)2(-OMe)(-Cl)]2– to the present [Re4Cl8(-O)2(-Cl)2]2–. These metallocyclobutadiynes can be viewed as products of the 2,2-cycloaddition of two Re-Re quadruple bonds, but the mechanistic details of how they arise remain obscure. 相似文献
8.
9.
Frédéric Blanc Christophe Copéret Bernard Fenet 《Journal of organometallic chemistry》2005,690(23):5014-5026
The reaction of Mo(N)(CH2tBu)3 (1) and SiO2-(700) generates (SiO)Mo(NH)(CHtBu)(CH2tBu) (2) when performed in C6H6 (material [1/SiO2-(700)]C6H6). The grafting occurs presumably by protonation of the nitrido ligand to form an intermediate (SiO)Mo(NH)(CH2tBu)3 (3), a pentacoordinated complex, which decomposes into 2 and 2,2-dimethylpropane. While [1/SiO2-(700)]C6H6 is highly active in olefin metathesis, [1/SiO2-(700)]CH2Cl2 and [1/SiO2-(700)]THF are poorly active or inactive catalysts respectively. In contrast, when Mo(N)(CH2tBu)3 reacts with a molecular silanol derivative, a soluble model of the surface of SiO2-(700), it yields a very stable complex, (c-C5H9)7Si7O12SiO-Mo(NH)(CH2tBu)3 (3m), which does not spontaneously generate 2,2-dimethylpropane and an alkylidene complex in contrast to the surface complex. Moreover, 3m does not catalyse olefin metathesis at room temperature as it does not already contain the initiating carbene ligand, and it is necessary to heat up the reaction mixture to 110 °C to obtain low catalytic activity. Nevertheless, the complex 3m generates well-defined metallocarbenes when heated in the presence of PMe3: (c-C5H9)7Si7O12SiO-Mo(N)(CHtBu)(P(CH3)3)2 (4m) as a 10:1 mixture of its syn and anti rotamers with the loss of 2 equiv. of 2,2-dimethylpropane. 相似文献
10.
A. N. Nesmeyanov M. I. Rybinskaya E. A. Petrovskaya T. V. Popova 《Russian Chemical Bulletin》1972,21(7):1588-1589
Conclusions A new method was developed for the synthesis of -RCOCH=CHFe(CO)2C5H5- by the reaction of-iodovinyl ketones with [Fe(CO)2C5H5-]2. In this case it was demonstrated for the first time that the reaction of organic haloderivatives with [Fe(CO)2C5H5-]2 can be used for the synthesis of -RFe(CO)2C5H5-.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1646–1647, July, 1972. 相似文献
11.
Numerous experimental data for the cyclization of free radicals C·H2(CH2)nCH=CH2 cyclo-[(CH2)n+1CH(C·H2)], and C·H2(CH2)nCH=CHR cyclo-[(CH2)n+1C·HCHR] were analyzed in the framework of the parabolic model. The activation energy of thermoneutral (H
e = 0) cyclization E
e0 decreases linearly with an increase in the energy of cycle strain E
rsc: E
e0(n) (kJ mol–1) = 85.5 – 0.44E
rsc(n) (n is the number of atoms in the cycle). The activation entropy of cyclization S
# also depends on the cycle size: the larger the cycle, the lower S
#. A linear dependence of S
# on the difference between the entropies of formation S° of cyclic hydrocarbon and the corresponding paraffin was found: S
# = 1.00[S°(cycle) – S°(CnH2n+2)]. The E
e0 values coincide for cyclization reactions with the formation of the six-membered cycle and the bimolecular addition of alkyl radicals to olefins. 相似文献
12.
Summary The51V n. m. r. spectra of the compounds [Et4N][V(CO)6–nLn] (1) and 5-C5H5V(CO)4–nLn (2) [n = 1,2 (cis andtrans for2); L = PF3, P(OMe)3, PMe3, PPh2Me], [Et4N][V(CO)mL][m = 3–5; L = PhP(CH2CH2PPh2)2] andcis/trans-[5-C5H5V(CO)2L] are discussed on the basis of variations of the paramagnetic contribution
para
to the overall shielding of the51V nucleus. For anionic complexes,
para
increases (shielding decreases) as CO is successively replaced for PR3 (R F), while the neutral complexes exhibit a minimum shielding in disubstituted,trans-configuration compounds. PF3 complexes show a contrary trend throughout. These trends are explained by (i) decreased energy separation between highest occupied and lowest unoccupied molecular orbitals as the degeneracy is raised plus increased number of relevant transitions in molecules of lower point symmetry, and (ii) destabilization of -type m.o (1 and2) and of -type m.o. (1 only) as V-PR3 interactions become increasingly important relative to V-CO interactions.
para
also increases in the series PF3 < CO < P(OMe)3 < PMe3 < PPh2Me, following the inverted order of the -acceptor strength. M.o. results obtained from LCAO-SCCC calculations are presented for 5-C5H5V(CO)4 and [5-C5H5V(CO)3CN]–: the local diamagnetic contribution to the shielding for these complexes amounts to 1712 ppm and is considered almost constant for all vanadium compounds. The preparations of [Et4N][V(CO)5PF3], andcis-[Et4N]V(CO)4L2] (L = PF3, PPh2Me), [Et4N][V(PF3]6, 5-C5H5V(CO)3PF3,cis/trans-[5-C5H5V(CO)2(PF3)2],cis-[5-C5H5V(CO)2(PPh2Me)2] and [Et4N][5-C5H5V(CO)3CN] are reported. 相似文献
13.
14.
N. V. Podberezskaya N. V. Pervukhina S. V. Belaya I. G. Vasilieva S. V. Borisov 《Journal of Structural Chemistry》2001,42(4):617-627
The crystal structures of two polysulfide phases HoS1.885(5) (I) and HoS1.863(8) (II) were determined; the integer stoichiometric ratio was found to be Ho8S15. The data were collected on an Enraf-Nonius CAD-4 automatic diffractometer using the standard procedure (MoK, graphite monochromator, an absorption correction applied based on -scan data). Crystal I: space group P4/nmm, a = 3.820(1), c = 7.840(3) , V = 114.40(6) 3, Z = 2 for the composition HoS1.885(5), d
calc = 6.542 g/cm3, R = 0.0520 for 184 unique reflections with Ihkl > 2 I; crystal II: space group P21/m, a = 10.961(2), b = 11.465(2), c = 10.984(2) , = 91.27(3)°, V = 1380.0(4) 3, Z = 24 for the composition HoS1.863(8), d
calc = 6.486 g/cm3, R = 0.0596 for 5354 unique reflections with Ihkl > 2 I. In both compounds, the Ho atoms are surrounded by 9 (8+1 for three atoms in II) S atoms forming monocapped square antiprisms. The Ho–S distances vary from 2.717 to 3.067 irrespective of the type of ion [S2– or (S2)2–]; the maximal distance to the atoms completing the coordination is 3.684 . The compounds have PbFCl type structures composed of ...(S2)2–...Ho3+...S2–...S2–...Ho3+...(S2)2–... layer packets differently oriented in space relative to the unit cell axes. The S2–...S2– and S2–...(S2)2– interlayer distances are mostly shorter than the sum of the ionic radii and vary within the limits of 3.331-3.558 and 3.029-3.784 for the first and second types, respectively. For I, the calculated site occupancies and densities are given depending on the composition Ho-S2-x (x = 0.25-0); for II, the most probable formulas of rational compositions in the same range of x are presented. 相似文献
15.
Fomina I. G. Sidorov A. A. Aleksandrov G. G. Zhilov V. I. Ikorskii V. N. Novotortsev V. M. Eremenko I. L. 《Russian Chemical Bulletin》2004,53(1):114-117
Co-thermolysis of the tetranuclear trimethylacetate clusters M4(3-OH)2(OOCCMe3)6(HOEt)6 (M = Co or Ni; the reagent ratio was 1 : 1) in decalin (2 h, 170 °C) afforded the octanuclear heterometallic cluster Co6Ni2(4-O)2(2-OOCCMe3)6(3-OOCCMe3)6, which exhibits ferromagnetic properties at 10—8 K. 相似文献
16.
Gehan M. A. El-Subruiti Cecil F. Wells Ibrahim M. Sidahmed 《Journal of solution chemistry》1991,20(4):403-415
The solubility of salts [Co(3Rpy)4Cl2]2]ReCl6] has been determined in water + methanol mixtures. By comparing these with the solubilities of the salt Cs2ReCl6 and using calculated activity coefficients for the ions in the water+methanol mixtures, values for {G
t
o
(Co(3Rpy)4Cl
2
+
)–G
t
o
(Cs+)} can be determined where G
t
o
is the standard Gibbs free energy of transfer from water to an aqueous mixture. G
t
o
(Cs+) from the solvent sorting scale and from the TPTB scale are then used to calculate G
t
o
(Co(3Rpy)4Cl
2
+
). These two sets of values for G
t
o
(Co(3Rpy)4Cl
2
+
) on the differing scales are then inserted into a free energy cycle applied to the bond extension Co(3Rpy)4Cl
2
+
(initial state)Co(3Rpy)4Cl2++Cl– (transition state) for the solvolysis in water and in water + methanol mixtures to produce values for G
t
o
(Co(3Rpy)4Cl2+) using both scales. Data for the solubilites of [Copy4Cl2]2[ReCl6] and [Co(4Rpy)4Cl2]2[ReCl6] have been re-calculated to compare free energies of transfer for these complex cations with those specified above. 相似文献
17.
V. A. Maksakov V. P. Kirin V. A. Ershova S. V. Tkachev P. P. Semyannikov 《Russian Chemical Bulletin》1993,42(11):1898-1901
The reactions of cysteine ethyl ester with a series of triosmium clusters have been studied. Enantiomeric (-H)Os3{-SCH2CH(CO2Et)NH2}(CO)10 and diastereomeric (-H)Os3{-2-SCH2CH(CO2Et)NH2}(CO)9 forms of the optically active cluster complexes have been obtained. Diastereomeric clusters have been separated by TLC on Silufol plates. The treatment of the enantiomeric complex (-H)Os3{-SCH2CH(CO2Et)NH2}(CO)10 with the trimethylamine oxide yields the diastereomeric pair (-H)Os3{-2-SCH2CH(CO2Et)NH2}(CO)9. The structures of the complexes obtained have been established on the basis of IR,1H NMR and mass spectrometry as well as X-ray analysis data.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1981–1984, November, 1993. 相似文献
18.
Guoliang Li Yaoming Xie Henry F. Schaefer III 《Journal of organometallic chemistry》2010,695(2):244-4528
The unsaturated Fe2C2 tetrahedrane derivatives R2C2Fe2(CO)6 (R = Ph, tBu) are among the many products obtained from reactions of the alkynes RCCR with iron carbonyls. In this connection theoretical studies have been performed on the simplest such compounds H2C2Fe2(CO)n (n = 6, 5) for comparison with the experimentally known structure of the t-butyl derivative t-Bu2C2Fe2(CO)6 and in order to predict the decarbonylation pathways for such (alkyne)Fe2(CO)6 derivatives. These theoretical studies predict an Fe2C2 tetrahedrane structure for H2C2Fe2(CO)6 with a formal FeFe double bond very similar to the experimental structure for t-Bu2C2Fe2(CO)6. Decarbonylation of H2C2Fe2(CO)6 is predicted to give an H2C2Fe2(CO)5 isomer retaining the Fe2C2 tetrahedrane structure, with an FeFe double bond but with the unprecedented feature of a four-electron donor bridging carbonyl group in an M2C2 tetrahedrane structure. The formation of formal FeFe triple bonds appears to be avoided in even the higher energy H2C2Fe2(CO)5 structures. These include three triplet Fe2C2 tetrahedrane structures with formal FeFe double bonds as well as a coordinately unsaturated singlet structure, still with an FeFe double bond. 相似文献
19.
Yu. A. Belousov T. A. Kolosova E. A. Viktorova V. A. Sergeev B. N. Babin 《Russian Chemical Bulletin》1987,36(7):1529-1531
Conclusions The reaction of iron carbonyls with sodium alkylthiolates proceeds by redox-disproportionation through one-electron transfer to form the Fe2(CO)8
, Fe3(CO)11 Fe4(CO)13
, and Fe3(CO)12
radical-anions. Fe2(CO)6(SR)2 and Fe3(CO)9(SR)2
radical-anions are paramagnetic analogs of the reaction products, Fe2(CO)6(SR)2 and Fe3(CO)9(SR)2, and were detected by ESR spectroscopy.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1652–1654, July, 1987. 相似文献
20.
Tao Hong Li Chuan Ming Wang Shi Wen Yu Xiang Yi Liu Hui Fu Xiao Guang Xie 《Journal of Molecular Structure》2009,915(1-3):105-111
The reaction of ground-state Y with 2-butyne has been investigated in detail using B3LYP method. Four pathways for elimination of H2 were identified. Two isomers, Y(HCCC)CH3 and Y(H2CCCCH2) were assigned to the observed product, YC4H4. The calculated PESs suggest that the concerted H2-elimination leading to Y(H2CCCCH2) + H2 product is the most favorable pathway. For the elimination of CH3, combining the results of this work with our previous study on Y + propyne reaction, a general mechanism for the reactions of Y with 2-alkynes bearing RCCCH3 structure was established: Y + RCCCH3 → π-complex → TS(H-migration) → HY(CH2CC)R → TS (CC insertion) → (CH2)HYCCR → TS(H-migration) → H3CYCCR → CH3 + YC2R. Such mechanism was found to be always energetically more favorable than the direct sp–sp3 CC bond insertion mechanism. Further, such mechanism can also be applied to the elimination of CH4 and it can be described as: Y + CH3CCCH3 → π-complex → TS (H-migration) → HY(H2CCC)CH3 → TS(CC insertion) → (H2CCC)HYCH3 → TS(H-migration) → CH4 + YC3H2. 相似文献