269
salicylaldoximate ([Mn 6 ]) cluster has been used as SBU, the CX diacid was able to
connect the hexamanganese clusters alone into a 1D crystalline coordination polymer (Zaltariov et al. 2016). Suitable tests have revealed the self-organization of this
polymer in solution or in cast films as micelles or inverse micelles and vesicles
depending on the polarity of the solvent, while magnetic measurements showed the
presence of slow relaxation of magnetization due to the presence of [Mn(III) 6 ] clusters (Zaltariov et al. 2016). In contrast, another dicarboxylic acid, 3-bis(pcarboxyphenylene- ester-methylene)tetramethyldisiloxane (Table 11.5, entry 2)
forms with Cu(II), in presence of imidazole, an H-bonded supramolecular structure
containing complex metal units (Zaltariov et al. 2014b). Another siloxane- containing
acid, 1,3-bis(3-trimellitylimidopropyl)tetramethyldisiloxane (Table 11.5, entry 3),
was obtained, characterized and used by Cazacu et al. (2012) to prepare heterotrinuclear carboxylate {Fe 2 CoOSi n } cluster. In addition, by thiol-ene addition of
3-mercaptopropionic acid and thioglycolic acid onto disiloxane or cyclosiloxane
bearing vinyl groups, appropriate acids (Table 11.5, entries 4,5) have formed, which
are suitable as ligands for metals (Turcan-Trofin et al. 2019). Recently, Delmas et al.
(2017, 2019) prepared a very interesting siloxane-based hexacarboxylic acid
(Table 11.5, entry 6) which was applied in MOF construction obtaining a 3D triply
interpenetrated H-bonded organic framework of Zn(II) accommodating 1D
H-bonded chain polymers in their pores.
One of the substrates that most frequently undergo chemical modifications to
become ligands is 1,3-bis(3-aminopropyl)tetramethyldisiloxane commercially
available (Table 11.5, entry 7), which readily reacts with carbonyl compounds forming bis-azomethines. Schiff bases derived from this siloxane compound have thus
been reported with: 2,4-dihydroxybenzaldehyde, 2-chloro-2-hydroxybenzaldehyde,
2-hydroxy-5-nitrobenzaldehyde,
2-hydroxybenzaldehyde,
3,5-dibromo-2hydroxybenzaldehyde (Soroceanu et al. 2013; Vlad et al. 2018), 2,6-diformyl- 4-methylphenol (DFF) (Zaltariov et al. 2014a), 3,5-di-tert-butyl-2-hydroxyben zaldehyde
(Cazacu et al. 2015; Soroceanu et al. 2015; Shova et al. 2017b, 2019), 3-carboxylsalicylaldehyde (Shova et al. 2017a), o-vanillin (Vlad et al. 2016), pyrrole-2carbaldehyde (Vlad et al. 2012b) or ferrocenecarboxaldehyde (Vlad et al. 2012a). In
the latter case, an oligomeric siloxane diamine was also used. This amine has also
been used to obtain polyazomethine structures with alternating siloxane and organic
segments such as: 1,4- dihydroxyanthraquinone and 8-dihydroxy-1,4-naphthoquinone (Georén and Lindbergh 2003; Vlad et al. 2012a), which exhibit electrochemical activity and self- assembling capacity (Soroceanu et al. 2015). In addition to the
commercial diamine, another amine derivative was prepared by Zaltariov et al.
(2013) by reacting 1,3-bis(chloromethyl)tetramethyldisiloxane with sodium salt of
p-aminobenzoic acid, thus linking the p-aminobenzene to the siloxane through the
ester group (Table 11.5, entry 8).
The bonding or coupling of polar groups/segments to the highly hydrophobic di-,
oligo- or PDMSs imparts amphiphilic character to the functional silicones. Given
the high flexibility of the siloxane chain/segment, amphiphilic silicones are easily
self-assembled in selective solvents (Racles et al. 2008; Cazacu et al. 2009a, b;
Soroceanu et al. 2016; Zaltariov et al. 2016; Turcan-Trofin et al. 2019). This has
11 Reactive and Functional Silicones for Special Applications
salicylaldoximate ([Mn 6 ]) cluster has been used as SBU, the CX diacid was able to
connect the hexamanganese clusters alone into a 1D crystalline coordination polymer (Zaltariov et al. 2016). Suitable tests have revealed the self-organization of this
polymer in solution or in cast films as micelles or inverse micelles and vesicles
depending on the polarity of the solvent, while magnetic measurements showed the
presence of slow relaxation of magnetization due to the presence of [Mn(III) 6 ] clusters (Zaltariov et al. 2016). In contrast, another dicarboxylic acid, 3-bis(pcarboxyphenylene- ester-methylene)tetramethyldisiloxane (Table 11.5, entry 2)
forms with Cu(II), in presence of imidazole, an H-bonded supramolecular structure
containing complex metal units (Zaltariov et al. 2014b). Another siloxane- containing
acid, 1,3-bis(3-trimellitylimidopropyl)tetramethyldisiloxane (Table 11.5, entry 3),
was obtained, characterized and used by Cazacu et al. (2012) to prepare heterotrinuclear carboxylate {Fe 2 CoOSi n } cluster. In addition, by thiol-ene addition of
3-mercaptopropionic acid and thioglycolic acid onto disiloxane or cyclosiloxane
bearing vinyl groups, appropriate acids (Table 11.5, entries 4,5) have formed, which
are suitable as ligands for metals (Turcan-Trofin et al. 2019). Recently, Delmas et al.
(2017, 2019) prepared a very interesting siloxane-based hexacarboxylic acid
(Table 11.5, entry 6) which was applied in MOF construction obtaining a 3D triply
interpenetrated H-bonded organic framework of Zn(II) accommodating 1D
H-bonded chain polymers in their pores.
One of the substrates that most frequently undergo chemical modifications to
become ligands is 1,3-bis(3-aminopropyl)tetramethyldisiloxane commercially
available (Table 11.5, entry 7), which readily reacts with carbonyl compounds forming bis-azomethines. Schiff bases derived from this siloxane compound have thus
been reported with: 2,4-dihydroxybenzaldehyde, 2-chloro-2-hydroxybenzaldehyde,
2-hydroxy-5-nitrobenzaldehyde,
2-hydroxybenzaldehyde,
3,5-dibromo-2hydroxybenzaldehyde (Soroceanu et al. 2013; Vlad et al. 2018), 2,6-diformyl- 4-methylphenol (DFF) (Zaltariov et al. 2014a), 3,5-di-tert-butyl-2-hydroxyben zaldehyde
(Cazacu et al. 2015; Soroceanu et al. 2015; Shova et al. 2017b, 2019), 3-carboxylsalicylaldehyde (Shova et al. 2017a), o-vanillin (Vlad et al. 2016), pyrrole-2carbaldehyde (Vlad et al. 2012b) or ferrocenecarboxaldehyde (Vlad et al. 2012a). In
the latter case, an oligomeric siloxane diamine was also used. This amine has also
been used to obtain polyazomethine structures with alternating siloxane and organic
segments such as: 1,4- dihydroxyanthraquinone and 8-dihydroxy-1,4-naphthoquinone (Georén and Lindbergh 2003; Vlad et al. 2012a), which exhibit electrochemical activity and self- assembling capacity (Soroceanu et al. 2015). In addition to the
commercial diamine, another amine derivative was prepared by Zaltariov et al.
(2013) by reacting 1,3-bis(chloromethyl)tetramethyldisiloxane with sodium salt of
p-aminobenzoic acid, thus linking the p-aminobenzene to the siloxane through the
ester group (Table 11.5, entry 8).
The bonding or coupling of polar groups/segments to the highly hydrophobic di-,
oligo- or PDMSs imparts amphiphilic character to the functional silicones. Given
the high flexibility of the siloxane chain/segment, amphiphilic silicones are easily
self-assembled in selective solvents (Racles et al. 2008; Cazacu et al. 2009a, b;
Soroceanu et al. 2016; Zaltariov et al. 2016; Turcan-Trofin et al. 2019). This has
11 Reactive and Functional Silicones for Special Applications