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Purification of 1,1' Diheptyl 4,4' Bipyridinium Dibromide

IP.com Disclosure Number: IPCOM000085912D
Original Publication Date: 1976-Jun-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Duran, J: AUTHOR

Abstract

Viologen, which is 1,1'-diheptyl-4,4'-bipyridinium dibromide, was recrystallized from dry, distilled acetonitrile. It should be filtered while boiling to remove less soluble impurities. The filter used was the fluted type from Eaton-Dikeman Company. Upon cooling, the crystals were collected over a Whatman #2 paper filter.

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Purification of 1,1' Diheptyl 4,4' Bipyridinium Dibromide

Viologen, which is 1,1'-diheptyl-4,4'-bipyridinium dibromide, was recrystallized from dry, distilled acetonitrile. It should be filtered while boiling to remove less soluble impurities. The filter used was the fluted type from Eaton- Dikeman Company. Upon cooling, the crystals were collected over a Whatman #2 paper filter.

Next, the sample is placed onto a vacuum jacketed reflux-chromatographic column using positive N flow and using only a medium-pore fritted glass support. Again the solvent used was dry, distilled acetonitrile The first collection of about one gram was discarded along with the solvent. Collection of the sample ensued using fresh solvent. About one gram of sample was left behind on the column. Following crystallization, the crystals were again collected over a Whatman paper filter. Finally the sample was vacuum dried at 50 Degrees C for 3 hours.

Results: Based on DSC measurements at least 3 impurities were removed from the starting material. The melting point (transition point) was raised from 293 Degrees C (Dec) to Approximately Equal 305 Degrees C (Dec). It should be noted that considerable improvement of the sample was gained following initial recrystallization. Purification of the sample improved performance in electrochromic memory display.

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