A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was med...A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was mediated by zirconocene. After iodination, three new compounds of 3,6-diiodo-4,5-dimethyl（dipropyl, dibutyl）-phthalic acid dimethyl esters （3a, 3b, 3c） were synthesized in high region-selectivity and yields, and characterized by NMR. The crystal structures were determined by single-crystal X-ray diffraction. The crystal of 3a （C12H121204, Mr = 474.02） belongs to the triclinic system, space group Pi with a = 7.6238（10）, b = 9.4571（12）, c = 10.8221（14） A, a = 66.611（10）, fl = 88.511（12）, 7 ： 77.604（11）% V= 697.93（16） A3, Z= 2, F（000） = 444, Dc = 2.256 mg/m3, g = 4.509 mm-1, T=133（2） K, S = 1.014, R = 0.0229 and wR = 0.0547 for 2644 observed reflections with I 〉 20（/）; the crystal of 3b （C16H201204, Mr - 530.12） is of triclinic system, space group Pi with a = 9.4122（19）, b = 10.626（2）, c = 11.353（2） A, a = 97.90（3）, fl = 113.83（3）, y = 110.22（3）°, V= 922.6（3） A3, Z- 2, F（000） = 508, Dc - 1.908 mg/m3, g = 3.422 mm-1, T = 113（2） K, S = 1.115, R = 0.0428 and wR = 0.1072 for 3971 observed reflections with I〉 20（/）; the crystal of 3c （ClsH241204, Mr = 558.17） belongs to the monoclinic system, space group P21/c with a = 26.396（2）, b = 8.7560（8）, c = 25.7970（18） A, fl = 91.721（4）o, V= 5959.6（8） A3, Z = 12, F（000） = 3240, Dc = 1.866 mg/m3,/z = 3.184 mm-l, T= 113（2） K, S = 1.154, R = 0.0424 and wR = 0.0766 for 13056 observed reflections with I 〉 20（/）.展开更多
In DMSO/water(4:1),photolysis of the dihydroxy-Sn(IV)-rnesoporphyrin dimethyl ester (SnP)/methyl viologen(MV^(2+))/ethylene diamine tetraacetic acid(EDTA)ternary system produces methyl viologen cation radical with a q...In DMSO/water(4:1),photolysis of the dihydroxy-Sn(IV)-rnesoporphyrin dimethyl ester (SnP)/methyl viologen(MV^(2+))/ethylene diamine tetraacetic acid(EDTA)ternary system produces methyl viologen cation radical with a quantum yield of 0.67,much higher than that of systems with other metal complexes of rnesoporphyrin dimethyl ester.Neither EDTA nor MV^(2+) quenches the stationary fluorescence of SnP,implying that the reaction does not take place at the singlet state.With flash photolysis we obtain the T-T absorption spectrum of SnP(λ_(max)-440 nm).By following the decay of this absorption,the triplet life time of SnP is estimated to be 41 μs.The life time is related to the concentration of either MV^(2+) or EDTA.Good linear relationships are obtained by plotting τ_0/τ vs.the concentration of MV^(2+) or EDTA(Stern-Volmer plot),from which we determine the quenching constants:k_q(MV^(2+))=5.5×10~7 mol^(-7) s^(-1);kq(EDTA)=2.7×10~7 mol^(-1),s^(-1).The data suggests that upon photolysis of the above ternary system,both oxidative quenching and reductive quenching of the triplet state of the sensitizer are occurring.From the measured phosphorescence spectrum(λ_(max) 704nm)and the ground state redox potentials (E_(1/2)^(red)～-0.84V,E_(1/2)^(ox)～ Ag/AgCl,KCl(sat.)),we obtain the redox potential of triplet SnP to be E (P^+/P)～-0.33 V, E(P/P-)～+0.92 V.Matching this data with the redox potential of MV^(2+) and EDTA,we establish the fact that during the photolysis of the SnP/MV^(2+)/EDTA ternary system,both oxidative and reductive quenching are thermodynamically favorable processes.This is also the reason why the SnP sensitized reaction is much more efficient relative to other mesoporphyrin derivatives.展开更多
以工业副产物混合二元酸(DBA)和甲醇为原料,用自制PW_(12)/SiO_2作催化剂制备混合酸二甲酯(DME),确定了最佳制箭条件:甲醇与DBA摩尔比为3.5,PW_(12)/SiO_2加入量(PW_(12)/SiO_2中PW_(12)占DBA的质量分数)为2%,反应时间为4.5 h,100 g DB...以工业副产物混合二元酸(DBA)和甲醇为原料,用自制PW_(12)/SiO_2作催化剂制备混合酸二甲酯(DME),确定了最佳制箭条件:甲醇与DBA摩尔比为3.5,PW_(12)/SiO_2加入量(PW_(12)/SiO_2中PW_(12)占DBA的质量分数)为2%,反应时间为4.5 h,100 g DBA中甲苯加入量为50 mL。在此最佳条件下,DME收率为84.7%,所得DME为无色澄清液体,其中丁二酸二甲酯的质量分数为11.03%,戊二酸二甲酯的质量分数为13.88%,己二酸二甲酯的质节分数为73.79%。PW_(12)/SiO_2具有较好的稳定性和一定的重复使用性,PW_(12)/SiO_2重复使用5次时的DME收率仍大于70%。展开更多
文摘A novel series of para-diiodobenzene derivatives, 3,6-diiodo-4,5-dialkyl-phthalic acid dimethyl esters, were prepared via cycloaddition of two TMS-substituted alkynes and dimethyl acetylenedicarboxylate, which was mediated by zirconocene. After iodination, three new compounds of 3,6-diiodo-4,5-dimethyl（dipropyl, dibutyl）-phthalic acid dimethyl esters （3a, 3b, 3c） were synthesized in high region-selectivity and yields, and characterized by NMR. The crystal structures were determined by single-crystal X-ray diffraction. The crystal of 3a （C12H121204, Mr = 474.02） belongs to the triclinic system, space group Pi with a = 7.6238（10）, b = 9.4571（12）, c = 10.8221（14） A, a = 66.611（10）, fl = 88.511（12）, 7 ： 77.604（11）% V= 697.93（16） A3, Z= 2, F（000） = 444, Dc = 2.256 mg/m3, g = 4.509 mm-1, T=133（2） K, S = 1.014, R = 0.0229 and wR = 0.0547 for 2644 observed reflections with I 〉 20（/）; the crystal of 3b （C16H201204, Mr - 530.12） is of triclinic system, space group Pi with a = 9.4122（19）, b = 10.626（2）, c = 11.353（2） A, a = 97.90（3）, fl = 113.83（3）, y = 110.22（3）°, V= 922.6（3） A3, Z- 2, F（000） = 508, Dc - 1.908 mg/m3, g = 3.422 mm-1, T = 113（2） K, S = 1.115, R = 0.0428 and wR = 0.1072 for 3971 observed reflections with I〉 20（/）; the crystal of 3c （ClsH241204, Mr = 558.17） belongs to the monoclinic system, space group P21/c with a = 26.396（2）, b = 8.7560（8）, c = 25.7970（18） A, fl = 91.721（4）o, V= 5959.6（8） A3, Z = 12, F（000） = 3240, Dc = 1.866 mg/m3,/z = 3.184 mm-l, T= 113（2） K, S = 1.154, R = 0.0424 and wR = 0.0766 for 13056 observed reflections with I 〉 20（/）.
文摘In DMSO/water(4:1),photolysis of the dihydroxy-Sn(IV)-rnesoporphyrin dimethyl ester (SnP)/methyl viologen(MV^(2+))/ethylene diamine tetraacetic acid(EDTA)ternary system produces methyl viologen cation radical with a quantum yield of 0.67,much higher than that of systems with other metal complexes of rnesoporphyrin dimethyl ester.Neither EDTA nor MV^(2+) quenches the stationary fluorescence of SnP,implying that the reaction does not take place at the singlet state.With flash photolysis we obtain the T-T absorption spectrum of SnP(λ_(max)-440 nm).By following the decay of this absorption,the triplet life time of SnP is estimated to be 41 μs.The life time is related to the concentration of either MV^(2+) or EDTA.Good linear relationships are obtained by plotting τ_0/τ vs.the concentration of MV^(2+) or EDTA(Stern-Volmer plot),from which we determine the quenching constants:k_q(MV^(2+))=5.5×10~7 mol^(-7) s^(-1);kq(EDTA)=2.7×10~7 mol^(-1),s^(-1).The data suggests that upon photolysis of the above ternary system,both oxidative quenching and reductive quenching of the triplet state of the sensitizer are occurring.From the measured phosphorescence spectrum(λ_(max) 704nm)and the ground state redox potentials (E_(1/2)^(red)～-0.84V,E_(1/2)^(ox)～ Ag/AgCl,KCl(sat.)),we obtain the redox potential of triplet SnP to be E (P^+/P)～-0.33 V, E(P/P-)～+0.92 V.Matching this data with the redox potential of MV^(2+) and EDTA,we establish the fact that during the photolysis of the SnP/MV^(2+)/EDTA ternary system,both oxidative and reductive quenching are thermodynamically favorable processes.This is also the reason why the SnP sensitized reaction is much more efficient relative to other mesoporphyrin derivatives.
文摘以工业副产物混合二元酸(DBA)和甲醇为原料,用自制PW_(12)/SiO_2作催化剂制备混合酸二甲酯(DME),确定了最佳制箭条件:甲醇与DBA摩尔比为3.5,PW_(12)/SiO_2加入量(PW_(12)/SiO_2中PW_(12)占DBA的质量分数)为2%,反应时间为4.5 h,100 g DBA中甲苯加入量为50 mL。在此最佳条件下,DME收率为84.7%,所得DME为无色澄清液体,其中丁二酸二甲酯的质量分数为11.03%,戊二酸二甲酯的质量分数为13.88%,己二酸二甲酯的质节分数为73.79%。PW_(12)/SiO_2具有较好的稳定性和一定的重复使用性,PW_(12)/SiO_2重复使用5次时的DME收率仍大于70%。
