Asam seleninat

Asam seleninat adalah senyawa organoselenium dan asam okso dengan rumus umum RSeO
2H, dengan R ≠ H. Strukturnya adalah R–Se(=O)–OH. Asam ini merupakan anggota pertama dari keluarga asam okso organoselenium, yang juga mencakup asam selenenat (R–Se–OH) dan asam selenonat (R–Se(=O)
2–OH). Anggota induk dari keluarga senyawa ini adalah asam metanaseleninat (CH
3–Se(=O)–OH), yang juga dikenal sebagai asam metilseleninat atau "MSA".

Reaksi dan kegunaan

Asam seleninat (terutama asam arenaseleninat) merupakan katalis yang berguna untuk epoksidasi hidrogen peroksida, oksidasi Baeyer–Villiger, oksidasi tioether, dll.; asam peroksiseleninat (R–Se(=O)–OOH) dianggap sebagai oksidan aktif.^[1]^[2]^[3]

Struktur dan sifat

Asam metanaseleninat telah dikarakterisasi melalui kristalografi sinar-X.^[4] Konfigurasi atom selenium berbentuk piramida, dengan Se-C = 1,925(8) Å, Se-O = 1,672(7) Å, Se-OH = 1,756(7) Å, sudut OSeO = 103,0(3)°, sudut HO-Se-C = 93,5(3)°, dan sudut OSeC = 101,4(3)°. Strukturnya isomorf dengan asam metanasulfinat.^[5]

Asam benzenaseleninat (C
6H
5–Se(=O)–OH' Too many ('";) sebelumnya telah dikarakterisasi melalui metode sinar-X^[6] dan resolusi optiknya telah dilaporkan.^[7]

Referensi

^ Ten Brink, Gerd-Jan; Fernandes, Bruno C. M.; Van Vliet, Michiel C. A.; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium catalysed oxidations with aqueous hydrogen peroxide. Part I: Epoxidation reactions in homogeneous solution". Journal of the Chemical Society, Perkin Transactions 1 (3): 224–228. doi:10.1039/b008198l.
^ Ten Brink, Gerd-Jan; Vis, Jan-Martijn; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium-Catalyzed Oxidations with Aqueous Hydrogen Peroxide. 2. Baeyer−Villiger Reactions in Homogeneous Solution¹". The Journal of Organic Chemistry. 66 (7): 2429–2433. doi:10.1021/jo0057710. PMID 11281784.
^ Mercier, Eric A.; Smith, Chris D.; Parvez, Masood; Back, Thomas G. (2012). "Cyclic Seleninate Esters as Catalysts for the Oxidation of Sulfides to Sulfoxides, Epoxidation of Alkenes, and Conversion of Enamines to α-Hydroxyketones". The Journal of Organic Chemistry. 77 (7): 3508–3517. doi:10.1021/jo300313v. PMID 22432805.
^ Block, Eric; Birringer, Marc; Jiang, Weiqin; Nakahodo, Tsukasa; Thompson, Henry J.; Toscano, Paul J.; Uzar, Horst; Zhang, Xing; Zhu, Zongjian (2001). "Allium Chemistry: Synthesis, Natural Occurrence, Biological Activity, and Chemistry of Se -Alk(en)ylselenocysteines and Their γ-Glutamyl Derivatives and Oxidation Products". Journal of Agricultural and Food Chemistry. 49 (1): 458–470. doi:10.1021/jf001097b. PMID 11305255.
^ Seff, K.; Heidner, E. G.; Meyers, M.; Trueblood, K. N. "The crystal and molecular structure of methanesulfinic acid." Acta Crystallographica Section B 1969, 25, 350–354.
^ Bryden, J. H.; McCullough, J. D. (1954). "The crystal structure of benzeneseleninic acid". Acta Crystallographica. 7 (12): 833–838. Bibcode:1954AcCry...7..833B. doi:10.1107/S0365110X54002551.
^ Shimizu, Toshio; Watanabe, Itaru; Kamigata, Nobumasa (2001). "Optically Active Seleninic Acids: Optical Resolution and Stability". Angewandte Chemie International Edition. 40 (13): 2460–2462. doi:10.1002/1521-3773(20010702)40:13<2460::AID-ANIE2460>3.0.CO;2-Q. PMID 11443664.

[1] Ten Brink, Gerd-Jan; Fernandes, Bruno C. M.; Van Vliet, Michiel C. A.; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium catalysed oxidations with aqueous hydrogen peroxide. Part I: Epoxidation reactions in homogeneous solution". Journal of the Chemical Society, Perkin Transactions 1 (3): 224–228. doi:10.1039/b008198l.

[2] Ten Brink, Gerd-Jan; Vis, Jan-Martijn; Arends, Isabel W. C. E.; Sheldon, Roger A. (2001). "Selenium-Catalyzed Oxidations with Aqueous Hydrogen Peroxide. 2. Baeyer−Villiger Reactions in Homogeneous Solution¹". The Journal of Organic Chemistry. 66 (7): 2429–2433. doi:10.1021/jo0057710. PMID 11281784.

[3] Mercier, Eric A.; Smith, Chris D.; Parvez, Masood; Back, Thomas G. (2012). "Cyclic Seleninate Esters as Catalysts for the Oxidation of Sulfides to Sulfoxides, Epoxidation of Alkenes, and Conversion of Enamines to α-Hydroxyketones". The Journal of Organic Chemistry. 77 (7): 3508–3517. doi:10.1021/jo300313v. PMID 22432805.

[4] Block, Eric; Birringer, Marc; Jiang, Weiqin; Nakahodo, Tsukasa; Thompson, Henry J.; Toscano, Paul J.; Uzar, Horst; Zhang, Xing; Zhu, Zongjian (2001). "Allium Chemistry: Synthesis, Natural Occurrence, Biological Activity, and Chemistry of Se -Alk(en)ylselenocysteines and Their γ-Glutamyl Derivatives and Oxidation Products". Journal of Agricultural and Food Chemistry. 49 (1): 458–470. doi:10.1021/jf001097b. PMID 11305255.

[5] Seff, K.; Heidner, E. G.; Meyers, M.; Trueblood, K. N. "The crystal and molecular structure of methanesulfinic acid." Acta Crystallographica Section B 1969, 25, 350–354.

[6] Bryden, J. H.; McCullough, J. D. (1954). "The crystal structure of benzeneseleninic acid". Acta Crystallographica. 7 (12): 833–838. Bibcode:1954AcCry...7..833B. doi:10.1107/S0365110X54002551.

[7] Shimizu, Toshio; Watanabe, Itaru; Kamigata, Nobumasa (2001). "Optically Active Seleninic Acids: Optical Resolution and Stability". Angewandte Chemie International Edition. 40 (13): 2460–2462. doi:10.1002/1521-3773(20010702)40:13<2460::AID-ANIE2460>3.0.CO;2-Q. PMID 11443664.

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