Metallo-celluloses, 1 Synthesis and solution properties of 4-ferrocenylbutylsubstituted cellulose derivatives

Abstract

An efficient method is described for the simultaneous introduction of 4-ferrocenylbutyl and n-hexyl side groups into cellulose. For this purpose, cellulose triacetate is treated in dimethyl sulfoxide/NaOH solution with mixtures of 4-bromobutylferrocene and n-hexyl bromide. An almost quantitative conversion of the cellulose hydroxyl groups was reached when less than one ferrocene substituent was attached to the cellulose repeating units on average. At higher degrees of ferrocene substitution, some of the cellulose hydroxyl groups seem to remain unsubstituted. This conclusion has been drawn on the basis of size exclusion chromatography (SEC) with online light-scattering detector where coil contraction was observed with increasing ferrocene content in the cellulose sample. This finding was further supported by IR spectroscopy, viscometry, and conventional SEC investigations. We assume that steric hindrance of the bulky side groups is responsible for incomplete conversion.

Metallo-celluloses, 2 Synthesis of cellulose derivatives bearing lateral bis-terpyridine ruthenium(II) complexes

“…In a first paper dealing with this topic, we reported on some ferrocene-containing cellulose derivatives A [14]. They were prepared from cellulose triacetate 1, a starting material which readily dissolves in dimethyl sulfoxide (DMSO) / NaOH solution.…”

Cellulose-Based Polymers with Long-Chain Pendant Ferrocene Derivatives as Organometallic Chromophores

“…22 Recently, polymers using ferrocene as main chain monomer or pendant side chain have been emphasized and their special properties have been illustrated. 22b,c, [23][24][25][26][27] As far as we are aware, there is only one report about cellulose-based ferrocenyl chromophores, 28 and still no report about ferrocenes as pendant substituents in cellulose derivatives, which allow a different functionalization in the 1-and 1′-position of the ferrocene chromophore. 29 Our design starts from 1,1′-distannylated ferrocene; 22a one stannyl substitution is used to construct the organometallic dipolar system, and the other one is used to introduce the linker to the cellulose.…”

“…The high chemical stability and facile modification of ferrocene has made it the springboard of organometallic chemistry, for example, by using selective transmetalation reactions, which enables the linkage of different functional groups to the two different Cp rings with high selectivity . Recently, polymers using ferrocene as main chain monomer or pendant side chain have been emphasized and their special properties have been illustrated. 22b,c,− As far as we are aware, there is only one report about cellulose-based ferrocenyl chromophores, and still no report about ferrocenes as pendant substituents in cellulose derivatives, which allow a different functionalization in the 1- and 1‘-position of the ferrocene chromophore . Our design starts from 1,1‘-distannylated ferrocene;22a one stannyl substitution is used to construct the organometallic dipolar system, and the other one is used to introduce the linker to the cellulose.…”