NOVELTY - Making substituted 5,5'-methylenebis(1H-pyrrole-2-thiol) compounds (IA) comprises reacting substituted aldehyde compounds (X) with substituted 1H-pyrrole-2-thiol compounds (XI).    USE - The method is useful for making substituted 5,5'-methylenebis(1H-pyrrole-2-thiol) compounds, which are used in the synthesis of porphyrin rods, where the porphyrin rods are useful: for producing molecular memory devices (all claimed); as light harvesting rods when immobilized or coupled to a substrate to produce light harvesting arrays and solar cells; as charge storage molecules; for information storage devices; and as active agents in photodynamic therapy.    ADVANTAGE - The method provides substituted 5,5'-methylenebis(1H-pyrrole-2-thiol) compounds having high purity with high yield and improved stability.    DETAILED DESCRIPTION - Making substituted 5,5'-methylenebis(1H-pyrrole-2-thiol) compounds of formula (IA) comprises reacting substituted aldehyde compounds of formula (D1L1CHO) (X) with substituted 1H-pyrrole-2-thiol compounds of formula (XI).    R1-R6 = H, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkenyl, cycloalkylalkynyl, heterocyclyl, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, aryloxy, arylalkyl, arylalkenyl, arylalkynyl, heteroaryl, heteroarylalkyl, heteroarylalkenyl, heteroarylalkynyl, alkoxy, halo, mercapto, azido, CN, acyl, formyl, carboxy, acylamino, ester, amide, OH, NO2, alkylthio, NH2, alkylamino, arylalkylamino, disubstituted NH2, acyloxy, sulfoxy, sulfonyl, sulfonate, sulfonic acid, sulfonamide, urea, alkoxyacylamino, aminoacyloxy, linking groups, surface attachment groups, bioconjugatable groups, targeting groups or water soluble groups;    D1 = R1 or substituted di(1H-pyrrol-2-yl)methane moiety of formula (a-1); and    L1 = linker or covalent bond.    INDEPENDENT CLAIMS are also included for:    (1) making substituted 1,9-bis(thio)dipyrromethane compound of formula (I), comprising oxidizing (IA);    (2) making substituted di(1H-pyrrol-2-yl)methane compounds of formula (II) comprising desulfurizing and reducing (I) or desulfurizing (IA); and    (3) synthesizing porphyrin rod comprising (i) providing 1,9-bis(thio)dipyrromethane containing compounds of formula (A1-L1-B1) (XII), (ii) providing dipyrromethane containing compounds of formula (E1-L1-D2) (XIII), and (iii) condensing (XII) with (XIII) to produce an elongated hydrocarbyl compound of formula (A2-L2-D2) (XIV), with the linker group comprising at least one porphyrinic macrocycle.    A1 = substituted 1,9-bis(thio)dipyrromethane moiety of formula (a-2);    A2 = 1,9-bis(thio)dipyrromethyl;    B1 = substituted dipyrromethane-1,9-dicarbinol moiety of formula (a-3) or dipyrromethane-1,9-dicarbinol;    E1 = substituted dipyrromethane moiety of formula (a-4) or dipyrromethane;    D2 = (a-1), 1,9-diacyldipyrromethane or surface attachment group; and    L2 = linker group.