[structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the ter... more [structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the terminal alkynes 1-pentyne, 1-hexyne, 1-heptyne, 1-octyne, 1-nonyne, and 1-decyne to form trans-1,2-bis(5-thianthreniumyl)alkene tetrafluoroborates (1-6). Similarly, addition of phenoxathiin cation radical tetrafluoroborate (PO*+ BF4(-)) to the same alkynes gave 1,2-bis(10-phenoxathiiniumyl)alkene tetrafluoroborates (7-12). The trans configuration of two of the adducts (1 and 4) was shown with X-ray crystallography. When solutions of 1-6 in chloroform were stirred with activated alumina, cis elimination of a proton and thianthrene (Th) occurred with the formation of 1-(5-thianthreniumyl)alkyne tetrafluoroborates (1a-6a). Similar treatment of 8-12 caused elimination of a proton and phenoxathiin (PO) with formation of 1-(10-phenoxathiiniumyl)alkene tetrafluoroborates (8a-12a). Stirring of 1a-6a with alumina for short periods of time caused their conversion into 5-[(alpha-keto)alkyl]thianthrenium ylides (1b-6b) and alpha-ketols, RC(O)CH2OH (1c-6c).
Journal of materials chemistry. A, Materials for energy and sustainability, 2017
As the most widely used synthetic material on the planet, concrete poses a serious societal conce... more As the most widely used synthetic material on the planet, concrete poses a serious societal concern regarding its significant environmental footprint.
Phenoxathiin cation radical perchlorate (PO.+ClO4(-)) added stereospecifically to cyclopentene, c... more Phenoxathiin cation radical perchlorate (PO.+ClO4(-)) added stereospecifically to cyclopentene, cyclohexene, cycloheptene, and 1,5-cyclooctadiene to give 1,2-bis(5-phenoxathiiniumyl)cycloalkane diperchlorates (4-7) in good yield. The diaxial configuration of the PO+ groups was confirmed with X-ray crystallography. Unlike additions of thianthrene cation radical perchlorate (Th.+ClO4(-)) to these cycloalkenes, no evidence for formation of monoadducts was found in the reactions of PO.+ClO4(-). This difference is discussed. Addition of Th.+ClO4(-) to five trans alkenes (2-butene, 2-pentene, 4-methyl-2-pentene, 3-octene, 5-decene) and four cis alkenes (2-pentene, 2-hexene, 2-heptene, 5-decene) gave in each case a mixture of mono- and bisadducts in which the configuration of the alkene was retained. Thus, cis alkenes gave erythro monoadducts and threo bisadducts, whereas trans alkenes gave threo monoadducts and erythro bisadducts. In these additions to alkenes, cis alkenes gave predominantly bisadducts, while trans alkenes (except for trans-2-butene) gave predominantly monoadducts. This difference is explained. 1,2-Bis(5-phenoxathiiniumyl)cycloalkanes (4-7) and 1,2-bis(5-thianthreniumyl)cycloalkanes underwent fast elimination reactions on activated alumina forming, respectively, 1-(5-phenoxathiiniumyl)cycloalkenes (8-11) and 1-(5-thianthreniumyl)cycloalkenes (12-16). Among adducts of Th.+ClO4(-) and alkenes, monoadducts underwent fast ring opening on alumina to give (5-thianthreniumyl)alkenes, while bisadducts underwent fast eliminations of H+ and thianthrene (Th) to give (5-thianthreniumyl)alkenes also. Ring opening of monoadducts was a stereospecific reaction in which the configuration of the original alkene was retained. Thus, erythro monoadducts (from cis alkenes) gave (E)-(5-thianthreniumyl)alkenes and threo monoadducts (from trans alkenes) gave (Z)-(5-thianthreniumyl)alkenes. Among bisadducts, elimination of a proton and Th occurred and was more complex, giving both (E)- and (Z)-(5-thianthreniumyl)alkenes. These results are explained. Configurations of adducts and (5-thianthreniumyl)alkenes were deduced with the aid of X-ray crystallography and (1)H and (13)C NMR spectroscopy. In the NMR spectra of (E)- and (Z)-(5-thianthreniumyl)alkenes, the alkenyl proton of Z isomers always appeared at a lower field (0.8-1.0 ppm) than that of E isomers.
[structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the ter... more [structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the terminal alkynes 1-pentyne, 1-hexyne, 1-heptyne, 1-octyne, 1-nonyne, and 1-decyne to form trans-1,2-bis(5-thianthreniumyl)alkene tetrafluoroborates (1-6). Similarly, addition of phenoxathiin cation radical tetrafluoroborate (PO*+ BF4(-)) to the same alkynes gave 1,2-bis(10-phenoxathiiniumyl)alkene tetrafluoroborates (7-12). The trans configuration of two of the adducts (1 and 4) was shown with X-ray crystallography. When solutions of 1-6 in chloroform were stirred with activated alumina, cis elimination of a proton and thianthrene (Th) occurred with the formation of 1-(5-thianthreniumyl)alkyne tetrafluoroborates (1a-6a). Similar treatment of 8-12 caused elimination of a proton and phenoxathiin (PO) with formation of 1-(10-phenoxathiiniumyl)alkene tetrafluoroborates (8a-12a). Stirring of 1a-6a with alumina for short periods of time caused their conversion into 5-[(alpha-keto)alkyl]thianthrenium ylides (1b-6b) and alpha-ketols, RC(O)CH2OH (1c-6c).
Thianthrene cation radical salts, Th(*)(+) X(-)(X(-) = a, ClO(4)(-); b, PF(6)(-); c, SbF(6)(-)), ... more Thianthrene cation radical salts, Th(*)(+) X(-)(X(-) = a, ClO(4)(-); b, PF(6)(-); c, SbF(6)(-)), add to cycloalkenes (C(5)-C(8)) in acetonitrile (MeCN) to form 1,2-bis(5-thianthreniumyl)cycloalkane salts and 1,2-(5,10-thianthreniumdiyl)cycloalkane salts, most of which have now been isolated and characterized. These are called bis- (3, 6, 9, 12) and monoadducts (4, 7, 10, 13). The proportional amount of the monoadduct obtained in the initial stage of the reaction varied with the cycloalkene in the order C(6) < C(5) < C(7) < C(8). Thus, the ratio bis:mono for C(5) and C(7) was, respectively, about 80/20 and 50/50. In contrast, only about 5% of the C(6) monoadduct (7a) and none of 7b,c was obtained, while for C(8) none of the bisadducts 12a-c was found. Bisadducts 3 and 9 lost thianthrene (Th) slowly in MeCN solution and changed into monoadducts 4 and 10. A comparable change from 6a into 7a was not observed. The monoadducts, themselves, lost a proton slowly in dry MeCN and opened into 1-(5-thianthreniumyl)cycloalkenes (5, 8, 11, 14). With 3 and 9, particularly, it was possible to follow with NMR spectroscopy the succession of changes, for example, 3 to 4 to 5. The opening of a monoadduct was made faster by adding a small amount of water to the solution. The bisadducts of 4-methylcyclohexene (15a) and 1,5-cyclooctadiene (17a) were isolated and characterized. Although a small amount of monodduct (16a) of 4-methylcyclohexene was found with NMR spectroscopy, it could not be isolated. Bis- and monoadducts were obtained also in additions of Th(*)(+) ClO(4)(-) to acyclic alkenes, in relative amounts that, again, varied with the alkene. From cis-2-butene the dominant product was the bisadduct (18), while the monoaduct (19) was characterized with NMR spectroscopy but could not be isolated. In contrast, trans-3-hexene gave mainly the monoadduct (21), while the bis adduct (20) could not be isolated. With 4-methyl-cis-2-pentene, both bis- (22) and monoadduct (23) were isolated, the former being dominant. The conversion of 18 into 19 was characterized with NMR spectroscopy. In all cycloalkene bisadducts, the configurational relationship of the two thianthrenium groups was trans, while in the monoadducts, the bonds to the single thianthrene dication were (necessarily) cis. In both bis- and monoadducts of acyclic alkenes, the configuration of the alkene was retained. The mechanisms of addition with retention of configuration, of conversion of a bis- into a monoadduct, and of opening of a monoadduct are discussed. Products were identified with a combination of NMR spectroscopy, X-ray crystallography, elemental analysis, and (for cycloalkene adducts) reaction with thiophenoxide ion.
ABSTRACT Six new precursors for lead sulfide nanoparticles were synthesized by the reaction of le... more ABSTRACT Six new precursors for lead sulfide nanoparticles were synthesized by the reaction of lead acetate, with picolinic (Hpic), 2,6-dipicolinic (H(2)dipic) or salicylic (H(2)sal) acid followed by the addition of thiourea (tu) or thiosemicarbazide (ths). The compounds are "[Pb(Hsal)(2)(tu)(2)]" (1a), "Pb(Hsal)(2)-(thS)(3)center dot 2H(2)O" (1b), "Pb(pic)(2)(tu)" (2a), [Pb(pic)(2)(ths)(2)](2) (2b), [Pb(dipic)(tu)(H(2)O)](2)center dot 2H(2)O (3a), and [Pb(dipic)(ths)2] " 2H(2)O (3b). Compounds 2b, 3a, and 3b formed well-defined crystals and were characterized by single-crystal X-ray diffraction, while the remaining compounds were characterized spectroscopically and by elemental analyses. The precursors were decomposed in both aqueous and nonaqueous media leading to pure crystalline galena in all cases. Depending upon conditions truncated octahedra, dendrites, nanocubes, interlinked nanocubes, nanohexapods and cubes were obtained. To elucidate the effect of single-source precursors on the mechanism of growth of nanoparticles, we compared the decomposition results with PbS nanostructures synthesized from multiple-source precursors using lead acetate with thiourea or thiosemicarbazide.
Acta Crystallographica Section C-crystal Structure Communications, Oct 15, 1992
Acta Crystallographica Section C. Crystal Structure Communications. 0108-2701. short format (meta... more Acta Crystallographica Section C. Crystal Structure Communications. 0108-2701. short format (metal-organic compounds). Volume 48 Part 10 Pages 1836-1837 October 1992 Dichlorotetrakis(pyridine)nickel(II). RE Bachman, KH Whitmire, S. Mandal and PK Bharadwaj ...
[structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the ter... more [structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the terminal alkynes 1-pentyne, 1-hexyne, 1-heptyne, 1-octyne, 1-nonyne, and 1-decyne to form trans-1,2-bis(5-thianthreniumyl)alkene tetrafluoroborates (1-6). Similarly, addition of phenoxathiin cation radical tetrafluoroborate (PO*+ BF4(-)) to the same alkynes gave 1,2-bis(10-phenoxathiiniumyl)alkene tetrafluoroborates (7-12). The trans configuration of two of the adducts (1 and 4) was shown with X-ray crystallography. When solutions of 1-6 in chloroform were stirred with activated alumina, cis elimination of a proton and thianthrene (Th) occurred with the formation of 1-(5-thianthreniumyl)alkyne tetrafluoroborates (1a-6a). Similar treatment of 8-12 caused elimination of a proton and phenoxathiin (PO) with formation of 1-(10-phenoxathiiniumyl)alkene tetrafluoroborates (8a-12a). Stirring of 1a-6a with alumina for short periods of time caused their conversion into 5-[(alpha-keto)alkyl]thianthrenium ylides (1b-6b) and alpha-ketols, RC(O)CH2OH (1c-6c).
Journal of materials chemistry. A, Materials for energy and sustainability, 2017
As the most widely used synthetic material on the planet, concrete poses a serious societal conce... more As the most widely used synthetic material on the planet, concrete poses a serious societal concern regarding its significant environmental footprint.
Phenoxathiin cation radical perchlorate (PO.+ClO4(-)) added stereospecifically to cyclopentene, c... more Phenoxathiin cation radical perchlorate (PO.+ClO4(-)) added stereospecifically to cyclopentene, cyclohexene, cycloheptene, and 1,5-cyclooctadiene to give 1,2-bis(5-phenoxathiiniumyl)cycloalkane diperchlorates (4-7) in good yield. The diaxial configuration of the PO+ groups was confirmed with X-ray crystallography. Unlike additions of thianthrene cation radical perchlorate (Th.+ClO4(-)) to these cycloalkenes, no evidence for formation of monoadducts was found in the reactions of PO.+ClO4(-). This difference is discussed. Addition of Th.+ClO4(-) to five trans alkenes (2-butene, 2-pentene, 4-methyl-2-pentene, 3-octene, 5-decene) and four cis alkenes (2-pentene, 2-hexene, 2-heptene, 5-decene) gave in each case a mixture of mono- and bisadducts in which the configuration of the alkene was retained. Thus, cis alkenes gave erythro monoadducts and threo bisadducts, whereas trans alkenes gave threo monoadducts and erythro bisadducts. In these additions to alkenes, cis alkenes gave predominantly bisadducts, while trans alkenes (except for trans-2-butene) gave predominantly monoadducts. This difference is explained. 1,2-Bis(5-phenoxathiiniumyl)cycloalkanes (4-7) and 1,2-bis(5-thianthreniumyl)cycloalkanes underwent fast elimination reactions on activated alumina forming, respectively, 1-(5-phenoxathiiniumyl)cycloalkenes (8-11) and 1-(5-thianthreniumyl)cycloalkenes (12-16). Among adducts of Th.+ClO4(-) and alkenes, monoadducts underwent fast ring opening on alumina to give (5-thianthreniumyl)alkenes, while bisadducts underwent fast eliminations of H+ and thianthrene (Th) to give (5-thianthreniumyl)alkenes also. Ring opening of monoadducts was a stereospecific reaction in which the configuration of the original alkene was retained. Thus, erythro monoadducts (from cis alkenes) gave (E)-(5-thianthreniumyl)alkenes and threo monoadducts (from trans alkenes) gave (Z)-(5-thianthreniumyl)alkenes. Among bisadducts, elimination of a proton and Th occurred and was more complex, giving both (E)- and (Z)-(5-thianthreniumyl)alkenes. These results are explained. Configurations of adducts and (5-thianthreniumyl)alkenes were deduced with the aid of X-ray crystallography and (1)H and (13)C NMR spectroscopy. In the NMR spectra of (E)- and (Z)-(5-thianthreniumyl)alkenes, the alkenyl proton of Z isomers always appeared at a lower field (0.8-1.0 ppm) than that of E isomers.
[structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the ter... more [structure: see text] Thianthrene cation radical tetrafluoroborate (Th*+ BF4(-)) added to the terminal alkynes 1-pentyne, 1-hexyne, 1-heptyne, 1-octyne, 1-nonyne, and 1-decyne to form trans-1,2-bis(5-thianthreniumyl)alkene tetrafluoroborates (1-6). Similarly, addition of phenoxathiin cation radical tetrafluoroborate (PO*+ BF4(-)) to the same alkynes gave 1,2-bis(10-phenoxathiiniumyl)alkene tetrafluoroborates (7-12). The trans configuration of two of the adducts (1 and 4) was shown with X-ray crystallography. When solutions of 1-6 in chloroform were stirred with activated alumina, cis elimination of a proton and thianthrene (Th) occurred with the formation of 1-(5-thianthreniumyl)alkyne tetrafluoroborates (1a-6a). Similar treatment of 8-12 caused elimination of a proton and phenoxathiin (PO) with formation of 1-(10-phenoxathiiniumyl)alkene tetrafluoroborates (8a-12a). Stirring of 1a-6a with alumina for short periods of time caused their conversion into 5-[(alpha-keto)alkyl]thianthrenium ylides (1b-6b) and alpha-ketols, RC(O)CH2OH (1c-6c).
Thianthrene cation radical salts, Th(*)(+) X(-)(X(-) = a, ClO(4)(-); b, PF(6)(-); c, SbF(6)(-)), ... more Thianthrene cation radical salts, Th(*)(+) X(-)(X(-) = a, ClO(4)(-); b, PF(6)(-); c, SbF(6)(-)), add to cycloalkenes (C(5)-C(8)) in acetonitrile (MeCN) to form 1,2-bis(5-thianthreniumyl)cycloalkane salts and 1,2-(5,10-thianthreniumdiyl)cycloalkane salts, most of which have now been isolated and characterized. These are called bis- (3, 6, 9, 12) and monoadducts (4, 7, 10, 13). The proportional amount of the monoadduct obtained in the initial stage of the reaction varied with the cycloalkene in the order C(6) < C(5) < C(7) < C(8). Thus, the ratio bis:mono for C(5) and C(7) was, respectively, about 80/20 and 50/50. In contrast, only about 5% of the C(6) monoadduct (7a) and none of 7b,c was obtained, while for C(8) none of the bisadducts 12a-c was found. Bisadducts 3 and 9 lost thianthrene (Th) slowly in MeCN solution and changed into monoadducts 4 and 10. A comparable change from 6a into 7a was not observed. The monoadducts, themselves, lost a proton slowly in dry MeCN and opened into 1-(5-thianthreniumyl)cycloalkenes (5, 8, 11, 14). With 3 and 9, particularly, it was possible to follow with NMR spectroscopy the succession of changes, for example, 3 to 4 to 5. The opening of a monoadduct was made faster by adding a small amount of water to the solution. The bisadducts of 4-methylcyclohexene (15a) and 1,5-cyclooctadiene (17a) were isolated and characterized. Although a small amount of monodduct (16a) of 4-methylcyclohexene was found with NMR spectroscopy, it could not be isolated. Bis- and monoadducts were obtained also in additions of Th(*)(+) ClO(4)(-) to acyclic alkenes, in relative amounts that, again, varied with the alkene. From cis-2-butene the dominant product was the bisadduct (18), while the monoaduct (19) was characterized with NMR spectroscopy but could not be isolated. In contrast, trans-3-hexene gave mainly the monoadduct (21), while the bis adduct (20) could not be isolated. With 4-methyl-cis-2-pentene, both bis- (22) and monoadduct (23) were isolated, the former being dominant. The conversion of 18 into 19 was characterized with NMR spectroscopy. In all cycloalkene bisadducts, the configurational relationship of the two thianthrenium groups was trans, while in the monoadducts, the bonds to the single thianthrene dication were (necessarily) cis. In both bis- and monoadducts of acyclic alkenes, the configuration of the alkene was retained. The mechanisms of addition with retention of configuration, of conversion of a bis- into a monoadduct, and of opening of a monoadduct are discussed. Products were identified with a combination of NMR spectroscopy, X-ray crystallography, elemental analysis, and (for cycloalkene adducts) reaction with thiophenoxide ion.
ABSTRACT Six new precursors for lead sulfide nanoparticles were synthesized by the reaction of le... more ABSTRACT Six new precursors for lead sulfide nanoparticles were synthesized by the reaction of lead acetate, with picolinic (Hpic), 2,6-dipicolinic (H(2)dipic) or salicylic (H(2)sal) acid followed by the addition of thiourea (tu) or thiosemicarbazide (ths). The compounds are "[Pb(Hsal)(2)(tu)(2)]" (1a), "Pb(Hsal)(2)-(thS)(3)center dot 2H(2)O" (1b), "Pb(pic)(2)(tu)" (2a), [Pb(pic)(2)(ths)(2)](2) (2b), [Pb(dipic)(tu)(H(2)O)](2)center dot 2H(2)O (3a), and [Pb(dipic)(ths)2] " 2H(2)O (3b). Compounds 2b, 3a, and 3b formed well-defined crystals and were characterized by single-crystal X-ray diffraction, while the remaining compounds were characterized spectroscopically and by elemental analyses. The precursors were decomposed in both aqueous and nonaqueous media leading to pure crystalline galena in all cases. Depending upon conditions truncated octahedra, dendrites, nanocubes, interlinked nanocubes, nanohexapods and cubes were obtained. To elucidate the effect of single-source precursors on the mechanism of growth of nanoparticles, we compared the decomposition results with PbS nanostructures synthesized from multiple-source precursors using lead acetate with thiourea or thiosemicarbazide.
Acta Crystallographica Section C-crystal Structure Communications, Oct 15, 1992
Acta Crystallographica Section C. Crystal Structure Communications. 0108-2701. short format (meta... more Acta Crystallographica Section C. Crystal Structure Communications. 0108-2701. short format (metal-organic compounds). Volume 48 Part 10 Pages 1836-1837 October 1992 Dichlorotetrakis(pyridine)nickel(II). RE Bachman, KH Whitmire, S. Mandal and PK Bharadwaj ...
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