Adduct between a sp 2 hybridized carbon allotrope and a pyrrole derivative, wherein said pyrrole derivative is represented by formula wherein R 1, R 2, R 3, and R 4 are independently selected in the group consisting of: hydrogen, linear or branched C 1 -C 22 alkyl, linear or branched C 2 -C 22 alkenyl or alkynyl, aryl, linear or branched C 1 -C 22 alkyl-aryl, linear or branched C 2 -C 22 alkenyl-aryl, linear or branched C 2 -C 22 alkynyl-aryl, and heteroaryl; the dashed lines (a') and (b') independently represent a double bond or a single bond; and W, Y and Z are independently selected from the group consisting of: hydrogen, linear or branched C 1 -C 18 alkyl, linear or branched C 2 -C 18 alkenyl or alkynyl, and formulae - depicted below wherein R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14, R 15, R 16, R 17, R 18, R 19, R 20, and R 21 are independently selected from the group consisting of: hydrogen, linear or branched C 1 -C 18 alkyl, linear or branched C 2 -C 18 alkenyl or alkynyl, aryl, linear or branched C 1 -C 22 alkyl-aryl, linear or branched C 2 -C 22 alkenyl-aryl, linear or branched C 2 -C 22 alkynyl-aryl, heteroaryl, carboxyl, acyl-alkyl with linear or branched C 1 -C 18 alkyl, acyl-alkenyl or acyl-alkynyl with linear or branched C 2 -C 18 alkenyl and alkynyl, acyl-aryl, acyl-heteroaryl, and acyl-amine, wherein said aryl and heteroaryl groups are optionally substituted by one or more groups selected from C 1 -C 3 alkyl, carboxyl, and acyl-alkyl with C 1 -C 3 alkyl; or R 12 and R 13 together form a pyrrole ring optionally substituted by one or more C 1 -C 3 alkyl groups; and wherein m is an integer from 1 to 4, and n, o, p, q, r, and s are, independently of one another, an integer from 1 to 12; and wherein when both the dashed lines (a') and (b') represent a double bond, then formula is represented by formula wherein R 1 -R 4 and W, Y, and Z have the meanings stated above, and wherein at least one among W, Y, and Z is represented by one of formulae - above or when only one of the dashed lines (a') or (b') represents a double bond, then Y is hydrogen, W is a -CH 2 -S- group which together with the carbon in position "a" forms a 5-membered ring, and formula is represented by formula below wherein R 1 -R 4 and Z have the meanings stated above or, when both the dashed lines represent a single bond, then Y and W are both a -CH 2 -S- group, and each of these together with the carbons in position "a" and "b" forms a 5-membered ring, and formula is represented by formula wherein R 1 -R 4 and Z have the meanings stated above R 1, R 2, R 3, and R 4 are independently selected in the group consisting of: hydrogen, linear or branched C 1 -C 22 alkyl, linear or branched C 2 -C 22 alkenyl or alkynyl, aryl, linear or branched C 1 -C 22 alkyl-aryl, linear or branched C 2 -C 22 alkenyl-aryl, linear or branched C 2 -C 22 alkynyl-aryl, and heteroaryl; the dashed lines (a') and (b') independently represent a double bond or a single bond; and W, Y and Z are independently selected from the group consisting of: hydrogen, linear or branched C 1 -C 18 alkyl, linear or branched C 2 -C 18 alkenyl or alkynyl, and formulae - depicted below wherein R 5, R 6, R 7, R 8, R 9, R 10, R 11, R 12, R 13, R 14, R 15, R 16, R 17, R 18, R 19, R 20, and R 21 are independently selected from the group consisting of: hydrogen, linear or branched C 1 -C 18 alkyl, linear or branched C 2 -C 18 alkenyl or alkynyl, aryl, linear or branched C 1 -C 22 alkyl-aryl, linear or branched C 2 -C 22 alkenyl-aryl, linear or branched C 2 -C 22 alkynyl-aryl, heteroaryl, carboxyl, acyl-alkyl with linear or branched C 1 -C 18 alkyl, acyl-alkenyl or acyl-alkynyl with linear or branched C 2 -C 18 alkenyl and alkynyl, acyl-aryl, acyl-heteroaryl, and acyl-amine, wherein said aryl and heteroaryl groups are optionally substituted by one or more groups selected from C 1 -C 3 alkyl, carboxyl, and acyl-alkyl with C 1 -C 3 alkyl; or R 12 and R 13 together form a pyrrole ring optionally substituted by one or more C 1 -C 3 alkyl groups; and wherein m is an integer from 1 to 4, and n, o, p, q, r, and s are, independently of one another, an integer from 1 to 12; and wherein when both the dashed lines (a') and (b') represent a double bond, then formula is represented by formula wherein R 1 -R 4 and W, Y, and Z have the meanings stated above, and wherein at least one among W, Y, and Z is represented by one of formulae - above or when only one of the dashed lines (a') or (b') represents a double bond, then Y is hydrogen, W is a -CH 2 -S- group which together with the carbon in position "a" forms a 5-membered ring, and formula is represented by formula below wherein R 1 -R 4 and Z have the meanings stated above or, when both the dashed lines represent a single bond, then Y and W are both a -CH 2 -S- group, and each of these together with the carbons in position "a" and "b" forms a 5-membered ring, and formula is represented by formula wherein R 1 -R 4 and Z have the meanings stated above