玫棕酸

玫棕酸
	IUPAC名; 5,6-Dihydroxycyclohex-5-ene-1,2,3,4-tetrone; 5,6-二羥基-5-環己烯-1,2,3,4-四酮
別名	二羥基二喹啉; 二氧二醌; 玫瑰紅酸
識別
CAS號	118-76-3（二水合物）
PubChem	67050
ChemSpider	60401
SMILES	C1(=C(C(=O)C(=O)C(=O)C1=O)O)O;
InChI	1/C6H2O6/c7-1-2(8)4(10)6(12)5(11)3(1)9/h7-8H;
InChIKey	WCJLIWFWHPOTAC-UHFFFAOYAV
EINECS	204-276-5
MeSH	C005690
性質
化學式	C6H2O6
熔點	130 - 132 °C（271 K）
	若非註明，所有數據均出自標準狀態（25 ℃，100 kPa）下。

玫棕酸（英語：Rhodizonic acid）是化學式為C
6H
2O
6或(CO)
4(COH)
2的化合物。它可以看作是環己烯的二重烯醇和四重酮。

玫棕酸通常以二水合物C
6H
2O
6 · 2H₂O的形式獲得。後者實際上是2,3,5,5,6,6-六羥基-2-環己烯-1,4-二酮，其中兩個原始酮基團被兩對偕二醇取代。二水合物經低壓升華可得橙色至深紅色、吸濕性強的無水酸。^[1]^[2]

與許多其他烯醇一樣，玫棕酸可以從羥基中失去氫正離子H⁺（pK_a1 = 7000437800000000000♠4.378±0.009, pK_a2 = 7000465200000000000♠4.652±0.014 at 25 °C）^[3]，產生玫棕酸氫根陰離子C
6HO−
6和玫棕酸根陰離子C
6O2−
6。後者芳香族和對稱，因為雙鍵的離域電子均勻分布在六個CO單元上。玫棕酸鹽往往具有各種深淺不一的紅色，從淡黃色到紫色。

玫棕酸已用於鋇、鉛和其他金屬的化學分析。^[4]特別是玫棕酸鈉測試可用於檢測受試者手中的槍擊殘留物（其中含鉛）^[5]，並區分箭傷和槍傷以執行狩獵法規。^[6]

歷史

1837年，奧地利化學家約翰·海勒通過分析加熱碳酸鉀和木炭混合物的產物發現了玫棕酸。 ^[7]^[8]^[9]這個名字來自希臘語ῥοδίζω（rhodizō，「染紅」）^[10]，由於其鹽的顏色。

化學性質

鹽

玫棕酸鹽在透射光中往往具有各種深淺的紅色，從淡黃色到紫色，在反射光中具有綠色光澤。

可以通過用硝酸氧化肌醇並在氧氣的存在下與乙酸鉀反應製備玫棕酸鉀。由於其在水中的相對難溶性，玫棕酸鹽可從溶液中結晶。^[11]

玫棕酸鈉呈深棕色，在乾燥時穩定^[12]，但水溶液會在幾天內分解，即使在冰箱中也是如此。^[4]玫棕酸鉛是深紫色的。^[12]^[13]

氧化和分解

玫棕酸是氧化產物鏈的成員：苯六酚（(COH)
6）、四羥基對苯醌（THBQ）（(COH)
4(CO)
2）、玫棕酸（(COH)
2(CO)
4）和環己六酮（(CO)
6）。^[4]已考慮將玫棕酸鋰與THBQ 鹽和苯六酚一起用於可充電電池中。^[14]一價陰離子C
6O−
6已在質譜實驗中檢測到。^[15]

玫棕酸和玫棕酸根陰離子可以失去一個CO單元以產生克酮酸（(CO)
3(COH)
2）和克酮酸根陰離子（C
5O2−
5），其機制仍然未完全了解。在鹼性溶液（pH>10）中，玫棕酸在沒有氧氣的條件下迅速轉化為THBQ陰離子（(CO)4−
6）而在有氧氣的情況下則轉化為克酮酸。在pH=8.3和光照條件下，溶液在沒有氧氣的情況下可以穩定數天，在有氧氣的情況下分解成克酮酸和其他產物（可能包括環己六酮或十二羥基環己烷）。^[16]^[17]

結構

酸

在溶液中，玫棕酸和玫棕酸氫根離子大部分是水合的，一些羰基>C=O被偕羥基>C(OH)
2取代。^[3]

鹽

在無水玫棕酸銣（Rb
2C
6O
6）中，玫棕酸陰離子以平行柱狀堆積，銣離子也是如此。在垂直於柱的平面中，它們排列成兩個交錯的六邊形網格。陰離子是平面的。^[2]

無水玫棕酸鉀（K
2C
6O
6）具有獨特但相似的結構。陰離子和陽離子排列在交替的平面上。在每個平面內，陰離子排列成六邊形網格。每個鉀離子的排列方式使其對稱地連接到四個陰離子上的八個氧，每個相鄰平面有兩個。陰離子略微扭曲成船形（與平均平面的rms偏差為0.108Å）。^[18]玫棕酸鈉（Na
2C
6O
6）具有相同的結構，但陰離子稍有扭曲（rms為0.113Å）^[19]

在溶液中，玫棕酸根陰離子不會水合。^[3]

參見

乙炔二醇 (COH)
2
三角酸 (CO)(COH)
2
方酸 (CO)
2(COH)
2
巴豆酸 (CO)
3(COH)
2

參考資料

^ Patton, E.; West, R. New aromatic anions. VIII. Acidity constants of rhodizonic acid. Journal of Physical Chemistry. 1970, 74 (12): 2512–2518. doi:10.1021/j100706a018.
^ ^2.0 ^2.1 Braga, D.; Cojazzi, G.; Maini, L.; Grepioni, F. Reversible solid-state interconversion of rhodizonic acid H₂C₆O₆ into H₆C₆O₈ and the solid-state structure of the rhodizonate dianion C
6O2−
6 (aromatic or non-aromatic?). New Journal of Chemistry. 2001, 25: 1221−1223. doi:10.1039/b107317f.
^ ^3.0 ^3.1 ^3.2 Gelb, R. I.; Schwartz, L. M.; Laufer, D. A. The structure of aqueous rhodizonic acid. Journal of Physical Chemistry. 1978, 82 (18): 1985–1988. doi:10.1021/j100507a006.
^ ^4.0 ^4.1 ^4.2 Chalmers, R. A.; Telling, G. M. A reassessment of rhodizonic acid as a qualitative reagent. Microchimica Acta. 1967, 55 (6): 1126–1135. S2CID 98540174. doi:10.1007/BF01225955.
^ Di Maio, V. J. M. Gunshot Wounds: Practical aspects of firearms, ballistics, and forensic techniques 2nd. CRC. 1998: 341. ISBN 0-8493-8163-0.
^ Glover, R. L. Detecting lead in "arrow" wounds in deer using rhodizonic acid. Wildlife Society Bulletin. 1981, 9 (3): 216–219. JSTOR 3781843.
^ Heller, J. F. Die Rhodizonsäure, eine aus den Produkten der Kaliumbereitung gewonnene neue Säure, und ihre chemischen Verhältnisse [Rhodizonic acid, one of the new acids derived from potassium preparations, and its chemical composition]. Justus Liebigs Annalen der Pharmacie. 1837, 24 (1): 1–16 [2009-07-08]. （原始內容存檔於2022-01-08）.
^ Turner, E.; Gregory, W.; Parnell, E. A.; Liebig, J.; Rogers, J. B. Elements of Chemistry. Thomas, Cowperthwait & Co. 1846 [2009-07-30]. （原始內容存檔於2022-01-08）. When potassium is heated in carbonic acid gas, combination takes place, and a dark olive powder is formed, composed of carbonic oxide and potassium, in the proportion C₇O₇+K₃, or 7CO+3K. This substance is formed in large quantity in the preparation of potassium from carbonate of potash and charcoal, and is the source of great loss and inconvenience. No such compound is formed with sodium, for which reason that metal may be more cheaply prepared than potassium.
^ Löwig, C. Chemie der organischen Verbindungen [Chemistry of Organic Compounds]. Zürich: F. Schultess. 1839.
^ Hunter, R.; Morris, C. (編). Universal Dictionary of the English language. New York: Collier. 1900 [2009-08-07].
^ Preisler, P. W.; Berger, L. Preparation of Tetrahydroxyquinone and Rhodizonic Acid Salts from the Product of the Oxidation of Inositol with Nitric Acid. Journal of the American Chemical Society. 1942, 64 (1): 67–69. doi:10.1021/ja01253a016.
^ ^12.0 ^12.1 Feigl, F.; Oesper, R. E. Spot Tests in Organic Analysis. 1960 [2009-07-30]. （原始內容存檔於2022-01-08）.
^ Gmelin, L.; Watts, H. Hand-book of Chemistry. Cavendish Society. 1856.
^ Chen, H.; Armand, M.; Courty, M.; Jiang, M.; Grey, C. P.; Dolhem, F.; Tarascon, J.-M.; Poizot, P. Lithium salt of tetrahydroxybenzoquinone: toward the development of a sustainable Li-ion battery. Journal of the American Chemical Society. 2009, 131 (25): 8984–8. PMID 19476355. doi:10.1021/ja9024897.
^ Wyrwas, R. B.; Chick Jarrold, C. Production of C
6O−
6 from oligomerization of CO on molybdenum anions. Journal of the American Chemical Society. 2006, 128 (42): 13688–9. PMID 17044687. doi:10.1021/ja0643927.
^ Iraci, G.; Back, M. H. The photochemistry of the rhodizonate dianion in aqueous solution. Canadian Journal of Chemistry. 1988, 66 (5): 1293. doi:10.1139/v88-209 .
^ Zhao, B.; Back, M. H. The photochemistry of the rhodizonate dianion in aqueous solution (PDF). Canadian Journal of Chemistry. 1991, 69 (3): 528 [2009-08-07]. doi:10.1139/v91-079. （原始內容 (PDF)存檔於2012-07-07）.
^ Cowan, J. A.; Howard, J. A. K. Dipotassium rhodizonate. Acta Crystallographica. 2004, E60 (4): m511–m513. doi:10.1107/S160053680400529X .
^ Dinnebier, R. E.; Nuss, H.; Jansen, M. Disodium rhodizonate: a powder diffraction study. Acta Crystallographica. 2005, E61 (10): m2148–m2150. doi:10.1107/S1600536805030552.

[patton-1] Patton, E.; West, R. New aromatic anions. VIII. Acidity constants of rhodizonic acid. Journal of Physical Chemistry. 1970, 74 (12): 2512–2518. doi:10.1021/j100706a018.

[braga2-2] 2.0 ^2.1 Braga, D.; Cojazzi, G.; Maini, L.; Grepioni, F. Reversible solid-state interconversion of rhodizonic acid H₂C₆O₆ into H₆C₆O₈ and the solid-state structure of the rhodizonate dianion C
6O2−
6 (aromatic or non-aromatic?). New Journal of Chemistry. 2001, 25: 1221−1223. doi:10.1039/b107317f.

[gelb1-3] 3.0 ^3.1 ^3.2 Gelb, R. I.; Schwartz, L. M.; Laufer, D. A. The structure of aqueous rhodizonic acid. Journal of Physical Chemistry. 1978, 82 (18): 1985–1988. doi:10.1021/j100507a006.

[chalmers-4] 4.0 ^4.1 ^4.2 Chalmers, R. A.; Telling, G. M. A reassessment of rhodizonic acid as a qualitative reagent. Microchimica Acta. 1967, 55 (6): 1126–1135. S2CID 98540174. doi:10.1007/BF01225955.

[5] Di Maio, V. J. M. Gunshot Wounds: Practical aspects of firearms, ballistics, and forensic techniques 2nd. CRC. 1998: 341. ISBN 0-8493-8163-0.

[Glover-6] Glover, R. L. Detecting lead in "arrow" wounds in deer using rhodizonic acid. Wildlife Society Bulletin. 1981, 9 (3): 216–219. JSTOR 3781843.

[heller-7] Heller, J. F. Die Rhodizonsäure, eine aus den Produkten der Kaliumbereitung gewonnene neue Säure, und ihre chemischen Verhältnisse [Rhodizonic acid, one of the new acids derived from potassium preparations, and its chemical composition]. Justus Liebigs Annalen der Pharmacie. 1837, 24 (1): 1–16 [2009-07-08]. （原始內容存檔於2022-01-08）.

[turner-8] Turner, E.; Gregory, W.; Parnell, E. A.; Liebig, J.; Rogers, J. B. Elements of Chemistry. Thomas, Cowperthwait & Co. 1846 [2009-07-30]. （原始內容存檔於2022-01-08）. When potassium is heated in carbonic acid gas, combination takes place, and a dark olive powder is formed, composed of carbonic oxide and potassium, in the proportion C₇O₇+K₃, or 7CO+3K. This substance is formed in large quantity in the preparation of potassium from carbonate of potash and charcoal, and is the source of great loss and inconvenience. No such compound is formed with sodium, for which reason that metal may be more cheaply prepared than potassium.

[loewig1-9] Löwig, C. Chemie der organischen Verbindungen [Chemistry of Organic Compounds]. Zürich: F. Schultess. 1839.

[hunter-10] Hunter, R.; Morris, C. (編). Universal Dictionary of the English language. New York: Collier. 1900 [2009-08-07].

[preisler-11] Preisler, P. W.; Berger, L. Preparation of Tetrahydroxyquinone and Rhodizonic Acid Salts from the Product of the Oxidation of Inositol with Nitric Acid. Journal of the American Chemical Society. 1942, 64 (1): 67–69. doi:10.1021/ja01253a016.

[feigl-12] 12.0 ^12.1 Feigl, F.; Oesper, R. E. Spot Tests in Organic Analysis. 1960 [2009-07-30]. （原始內容存檔於2022-01-08）.

[gmelinwa-13] Gmelin, L.; Watts, H. Hand-book of Chemistry. Cavendish Society. 1856.

[chen-14] Chen, H.; Armand, M.; Courty, M.; Jiang, M.; Grey, C. P.; Dolhem, F.; Tarascon, J.-M.; Poizot, P. Lithium salt of tetrahydroxybenzoquinone: toward the development of a sustainable Li-ion battery. Journal of the American Chemical Society. 2009, 131 (25): 8984–8. PMID 19476355. doi:10.1021/ja9024897.

[wyja-15] Wyrwas, R. B.; Chick Jarrold, C. Production of C
6O−
6 from oligomerization of CO on molybdenum anions. Journal of the American Chemical Society. 2006, 128 (42): 13688–9. PMID 17044687. doi:10.1021/ja0643927.

[iraci-16] Iraci, G.; Back, M. H. The photochemistry of the rhodizonate dianion in aqueous solution. Canadian Journal of Chemistry. 1988, 66 (5): 1293. doi:10.1139/v88-209 .

[zhao-17] Zhao, B.; Back, M. H. The photochemistry of the rhodizonate dianion in aqueous solution (PDF). Canadian Journal of Chemistry. 1991, 69 (3): 528 [2009-08-07]. doi:10.1139/v91-079. （原始內容 (PDF)存檔於2012-07-07）.

[cowan-18] Cowan, J. A.; Howard, J. A. K. Dipotassium rhodizonate. Acta Crystallographica. 2004, E60 (4): m511–m513. doi:10.1107/S160053680400529X .

[dinne-19] Dinnebier, R. E.; Nuss, H.; Jansen, M. Disodium rhodizonate: a powder diffraction study. Acta Crystallographica. 2005, E61 (10): m2148–m2150. doi:10.1107/S1600536805030552.

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