Crystal structure of 2,4-diselenouracil

✍ Scribed by Eli Shefter; Michael N. G. James; Henry G. Mautner

• Publisher: John Wiley and Sons
• Year: 1966
• Tongue: English
• Weight: 213 KB
• Volume: 55
• Category: Article
• ISSN: 0022-3549
• DOI: 10.1002/jps.2600550626

✦ Synopsis

The crystal structure of 2,4-diselenouracil has been determined to provide some quantitative molecular information about the nature of hydrogen bonding exhibited by this compound inosolution. T h e crystal is ommonoclinic, with space group P 2Jc, with a = 4.41 A.,b = 14.90 A., c = 10.69 A., and 0 = 108.4". T h e observed density is 2.42 Gm. ~m . -~ and that calculated for four molecules in the unit cell is 2.33 Gm. cm.?. The structure was determined by the heavy atom technique and refined by block diagonal least squares to an R value of 0.136. The compound was found to exist primarily in a zwitterionic amidic configuration rather than the keto form. The seleniums formed relatively strong hydrogen" bonds of the form N(H) ... Se with distances of 3.47 and 3.75 A.