01779nas a2200169   4500008004100000245011900041210006900160260000800229300001600237490000800253520113800261100001801399700002201417700002101439700001701460856013201477       2011                        eng d00aComparative study of porphyrin derivatives in monolayers at the air-water interface and in langmuir-blodgett films0 aComparative study of porphyrin derivatives in monolayers at the   cMAR  a8066–80730 v5193 a<p>The orientation and aggregation of various porphyrin derivatives at the air–water interface and in Langmuir–Blodgett films were investigated. Monolayer properties of these molecules, where long alkyl chain(s) were covalently bound through different functionality of varying hydrophilicity were studied by measuring surface pressure area isotherms. Such derivatives, where ether functionality (functionalities) was (were) used for linking long alkyl chain(s), did not form uniform monolayer; instead they were found to form multilayer clusters or aggregates on the water surface. On the other hand, porphyrin derivative functionalized at the four peripheral phenyl rings with eight hexadecyl ether chains formed stable spherical vesicles when deposited on mica. Tetra N-alkyl pyridinium porphyrins with long alkyl chain were found to form various phases on the water surface. Evidence of transition from horizontal orientation to vertical orientation of porphyrin rings of porphyrin molecules having C14 chains was observed. This type of transition was lost with the porphyrin molecule with a relatively smaller chain (C8).</p>1 aGhosh, Amrita1 aMahato, Prasenjit1 aChoudhury, Sipra1 aDas, Amitava  uhttps://library.ncl.res.in/content/comparative-study-porphyrin-derivatives-monolayers-air-water-interface-and-langmuir-blodgett00770nas a2200169   4500008004100000245009500041210006900136260000800205300001600213490000700229520016400236100002200400700001700422700002100439700001700460856012300477       2011                        eng d00aSolvent-dependent aggregation behavior of a new Ru(ii)-polypyridyl based metallosurfactant0 aSolventdependent aggregation behavior of a new Ruiipolypyridyl b  cSEP  a11074-110760 v473 a<p>Variation of the solvent polarity leads to the formation of vesicles and reverse vesicles of a newly synthesized amphiphilic Ru(II)-polypyridyl complex.</p>1 aMahato, Prasenjit1 aSaha, Sukdeb1 aChoudhury, Sipra1 aDas, Amitava  uhttps://library.ncl.res.in/content/solvent-dependent-aggregation-behavior-new-ruii-polypyridyl-based-metallosurfactant02275nas a2200169   4500008004100000245016000041210006900201260000800270300001600278490000700294520159700301100002201898700001701920700002101937700001701958856013001975       2012                        eng d00aInterfacial and film formation behavior of photoactive Ru(ii)bipyridyl based metallosurfactants and a rare example of a monolayer based logic gate approach0 aInterfacial and film formation behavior of photoactive Ruiibipyr  cDEC  a1096–11050 v773 a<p>Three derivatives of tris(bipyridyl)–ruthenium(II) complexes with different alkyl-chain lengths (nC18H37 (1), nC14H29 (2) and nC10H21 (3)) were synthesised. All these complexes behaved as an amphiphile and their surface properties were studied at the air–water interface by measuring surface pressure–area (Π–A) isotherms. The surface morphology of the resulting films at the air–water interface was also studied by using Brewster angle microscopy. Mean molecular areas of these complexes were measured from the Π–A isotherms, which were approximately 200 Å2, thereby indicating a parallel arrangement of the Ru–bipyridyl moiety of the complexes. Mono- and multilayer Langmuir–Blodgett (LB) films were formed on different solid surfaces with transfer ratios close to one. Similarities in the absorption and fluorescence spectra of these amphiphiles in solution as well as in LB films deposited on a quartz surface confirmed the successful transfer of these films onto the substrates. The latter provided information about the arrangements of metallosurfactant molecules within the LB films. The two-dimensional concentrations of these films were calculated from the Lambert–Beer law as well as from the Π–A isotherm, which confirmed regular and reproducible transfer of the complex monolayers from the air–water interface onto the quartz surface. The surface morphology of these films on various substrates was characterised by atomic force microscopy. Furthermore, by oxidising the monolayer of complex 3, a one-input sequential logic gate was constructed.</p>1 aMahato, Prasenjit1 aSaha, Sukdeb1 aChoudhury, Sipra1 aDas, Amitava  uhttps://library.ncl.res.in/content/interfacial-and-film-formation-behavior-photoactive-ruiibipyridyl-based-metallosurfactants