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Despite having good electronic properties, BODIPY (boron dipyrromethene) and its derivatives attract less research attention towards the development of BODIPY based molecular electronics. Here we have investigated the effect of alkyl chain length attached to BODIPY molecule on its diode and negative differential behaviour. An undecenyl‐BODIPY dye (BODIPY‐C11) was designed, synthesized and deposited on Si (111) surface which was further converted into a bilayer using another BODIPY dye, PM567. Various techniques were used to check the arrangement and thickness of the layers which established that the designed molecule is suitable for compact grafting on Si surface. Electrical behaviour of BODIPY‐C11 monolayer and bilayer showed rectification (rectification ratio=500) and NDR property (peak‐to‐valley ratio=1000), respectively with improved device performances as compared to the electrical characteristics shown by 2,6‐diethyl‐4,4‐difluoro‐1,3,5,7‐tetramethyl‐8‐(4'‐(4"‐penteneoxyphenyl)‐4‐bora‐3a,4a‐diaza‐s‐indecene (BODIPY‐C5) grafted on Si. This study established that the electrical behaviour of BODIPY can be modulated by simply changing the alkyl chain length, which will be useful for the development of BODIPY‐based electronic materials. [ABSTRACT FROM AUTHOR]

Amongst the various porphyrinoids, octaphyrin has attracted significant attention owing to its diverse syntheses, conformations, and metal-ligation properties. Octaphyrin is a higher homologue of porphyrin and is formed by linking together heterocycles such as pyrrole, furan, thiophene, and selenophene through α-α or α- meso carbon bonds. The planar conformation is mainly achieved through inversion of the heterocyclic units from the center of macrocycle; avoiding meso-bridges; introducing a para-quinodimethane bridge; employing a neo-confusion approach; protonation; and by generating dianionic species. In this Focus Review, recent synthetic advancements in the field of octaphyrins are summarized. The twisted conformation of the octaphyrin binds to two metal ions in a tetracoordinate geometry. The diphosphorus complex of octaphyrin represents the first example of a stable expanded isophlorin. [ABSTRACT FROM AUTHOR]

Bodipy laser dyes are highly efficient but degrade rapidly in solution by reacting with in situ generated singlet oxygen (1O2). To increase the lasing lifetimes of these dyes, we have designed and synthesised two different congeners of the widely studied Pyrromethene 567 (PM567) by substitution at the boron centre and/or at both the boron centre and the meso position. The two new dyes showed high lasing efficiencies with increased photostability. The results of theoretical and pulse radiolysis studies revealed that the substitution at the boron centre reduced the 1O2 generation capacity of these dyes as well as their rate of reaction with 1O2, thereby enhancing their lifetimes even under lasing conditions. [ABSTRACT FROM AUTHOR]