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been reported null/weak and strong biocidal effects (Petkovic et al.
2011
). The na-
ture of substituents in position R3 in the pyridine ring has a very big influence
on the toxicity (Petkovic et al.
2011
). Presence of an ester group into long alkyl
chains reduced toxicity and improved ecotoxicity of pyridine ILs (Pham et al.
2010
).
Bis(pyridinium) ILs are only slightly toxic to the microorganisms and showed ex-
tremely poor mineralization (Ford et al.
2010
). Pyridinium ILs with a C4 alkyl
chain at the one-position gave poor biodegradabilities, and the introduction of a
methyl group to the three-position of the pyridinium core do not increased biodegra-
dation (Coleman and Gathergood
2010
; Petkovic et al.
2011
; Harjani et al.
2008
,
2009
). Docherty et al. (
2007
) found that Py4-3Me Br is metabolized by the activated
sludge community (Pham et al.
2010
; Docherty et al.
2007
). Full mineralization was
achieved for specifically designed ILs as those constituted by pyridinium rings with
longer alkyl side chains or hydroxyl groups combined with biodegradable anions as
saccharinate or octylsulfate (Coleman and Gathergood
2010
; Stasiewicz et al.
2008
;
Abrusci et al.
2011
; Stolte et al.
2008
). Presence of a 1-(2-hydroxyethyl) side chain
showed high levels of biodegradation while methyl or ethyl ether side chains showed
significantly lower levels of biodegradability, acetal and carbamate functionalities
also showing low levels of mineralization (Ford et al.
2010
). Ester group in the
side chain of pyridinium ILs improved the primary biodegradability of the cation
(Coleman and Gathergood
2010
; Petkovic et al.
2011
; Harjani et al.
2009
). Pyridine
ILs with ester group in position “1” or an ester linkage from the 3-carboxy group on
pyridine ring are classified as readily biodegradable, while amide linkage from the
3-carboxy group form a IL with poor biodegradability (Coleman and Gathergood
2010
). In case of pyridine ILs the acesulfamate derivates gave better biodegradation
than the saccharinates (Coleman and Gathergood
2010
; Pham et al.
2010
; Stasiewicz
et al.
2008
). Recently was propose for Py4-3Me Br (1-butyl-3-methylpyridinium bro-
mide) two degradation pathway (Coleman and Gathergood
2010
; Pham et al.
2010
;
Petkovic et al.
2011
): one by Pham et al. (
2009
), which implies the hydroxilation of
the side chain, and the second pathway involve unsaturation of the alkyl side chain
and hydroxylation of the aromatic ring (Docherty et al.
2010
).
Being the exposed structural reaches of ILs a representative class of them will
be in this study employed for the quantum bondons search by the aid of computed
spectra in the Raman/IR regimes, while establishing the associate rules for their
experimental identification.
13.2
Bondonic Information with Raman Scattering (Putz
2010a
)
Just to give a conceptual glimpse of how the present bondonic approach
(Putz
2010a
,
b
; Putz and Ori
2015
, see Chap. 10; Putz et al.
2015a
,
b
, see Chaps. 11
and 12; Putz
2015
) may be employed, the scattering phenomena are considered within
its Raman realization (Smekal
1923
; Raman and Krishnan
1928
,
1929
; Landsberg
and Mandelstam
1928
), viewed as a sort of generalized Compton (
1923
) scatter-
ing process,
i.e.
, extracting the structural information from various systems (atoms,
