Catalytically active perrhenate based ionic liquids: a preliminary ecotoxicity and biodegradability assessment

Abstract

Recently it was shown that water and air stable perrhenate based ionic liquids (ILs) are promising catalysts for oxidation reactions. For a broader application and in the context of green chemistry it is important to study in addition to their technical performance also their potential impact on environment and human health. This paper presents the first account on (eco)toxicological and biodegradation data for a set of ammonium and imidazolium based ILs with perrhenate anions. Fig. 1 Illustration of the ammonium-and imidazolium perrhenates used in the study: [NBu 4 ][ReO 4 ] (1), [BnBnIm][ReO 4 ] (2), [MeHDecIm][ReO 4 ] (3), and [MeBn F Im][ReO 4 ] (4) (Bn = benzyl, Me = methyl, HDec = hexadecyl, Bn F = 2,3,4,5,6-pentafluorobenzyl, and Im = imidazolium).

Toward the Proactive Design of Sustainable Chemicals: Ionic Liquids as a Prime Example

“…For the simplest, i.e., the alkyl chain, there are certain minimum and maximum lengths that allow for degradation. If the alkyl substituent is shorter than eight carbon atoms, the whole cation is usually not degradable; however, if the chain is significantly longer than that, poor degradability can occur due to toxic inhibition of the activity of the microbial community . If functional groups prone to enzymatic attack are included in the IL’s structure, they favor degradability; for example, terminal hydroxyls, carboxyls, and esters , sometimes result in full primary degradation if the side chain is long enough .…”

“…If functional groups prone to enzymatic attack are included in the IL’s structure, they favor degradability; for example, terminal hydroxyls, carboxyls, and esters , sometimes result in full primary degradation if the side chain is long enough . In contrast, introduction of phenyl, ,,, allyl, nitrile, ether, , or amide ,− groups result in decreased degradability . The presence of halogen atoms impedes degradation and is not recommended (see Figure for detailed structure-biodegradability rules of imidazolium and quaternary ammonium ILs and Figure for general structure-biodegradability rules for ILs).…”

“…In contrast, introduction of phenyl, ,,, allyl, nitrile, ether, , or amide ,− groups result in decreased degradability . The presence of halogen atoms impedes degradation and is not recommended (see Figure for detailed structure-biodegradability rules of imidazolium and quaternary ammonium ILs and Figure for general structure-biodegradability rules for ILs).…”

Environmental properties of phosphonium, imidazolium and ammonium cation-based ionic liquids as potential lubricant additives

“…Various substituted imidazolium, phosphonium and quaternary ammonium derivatives have been screened for their biodegradability and, in general, they also exhibited low levels of biodegradation [77,89,110,[112][113][114][115].…”

Πειραματική Μελέτη Και Προσομοίωση Μιγμάτων Που Περιέχουν Τρίτης Γενιάς Ιοντικά Υγρά

“…H παρουσία ομάδων που περιέχουν πιθανές θέσεις ενζυμικής υδρόλυσης όπως για παράδειγμα το οξυγόνο (στη μορφή υδροξυλίων, αλδεϋδών ή καρβοξυλικών οξέων) καθώς επίσης και ετεροκυκλικών δακτυλίων και αλειφατικών αιθερικών δεσμών συμβάλλουν θετικά στην αποικοδόμηση των ΙΥ [113][114][115][116] . Όσον αφορά στην επίδραση του κατιόντος, τα ιμιδαζολικα ΙΥ, τα τετραλκυλαμμωνιακά ΙΥ, τα ΙΥ αλεικυκλικών οξέων και τα ΙΥ με βάση την πιπεριδίνη και τη μορφολίνη δεν είναι άμεσα βιοαποικοδομήσιμα [117][118][119][120][121][122][123][124] , με τα ιμιδαζολικά ΙΥ να είναι τα πιο ανθεκτικά στην αποικοδόμηση. Αντιθέτως, το κατιόν της χολίνης αποτελεί ένα από τα πιο βιοαποικοδομήσιμα κατιόντα.…”