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-metallosurfactant01715nas a2200205   4500008004100000245010600041210006900147260000800216300001400224490000800238520099700246100001801243700002201261700001801283700002401301700002101325700001701346700001701363856012901380       2011                        eng d00aUrea/thiourea derivatives and Zn(II)-DPA complex as receptors for anionic recognition-a brief account0 aUreathiourea derivatives and ZnIIDPA complex as receptors for an  cOCT  a175–1860 v1233 a<p>This review covers few examples of anion complexation chemistry, with a special focus on urea/thiourea-based receptors and Zn(II)-dipicolyl amine-based receptors. This article specially focuses on structural aspects of the receptors and the anions for obtaining the desire specificity along with an efficient receptor–anion interaction. Two types of receptors have been described in this brief account; first one being the strong hydrogen bond donor urea/thiourea derivatives, which binds the anionic analytes through hydrogen bonded interactions; while, the second type of receptors are coordination complexes, where the coordination of the anion to the metal centre. In both the cases the anion binding modulate the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and thereby the spectroscopic response. Appropriate choice of the signalling unit may allow probing the anion binding phenomena through visual detection.</p>1 aDas, Priyadip1 aMahato, Prasenjit1 aGhosh, Amrita1 aMandal, Amal, Kumar1 aBanerjee, Tanmay1 aSaha, Sukdeb1 aDas, Amitava  uhttps://library.ncl.res.in/content/ureathiourea-derivatives-and-znii-dpa-complex-receptors-anionic-recognition-brief-account01794nas a2200193   4500008004100000245018400041210006900225260000800294300001600302490000700318520102100325100002201346700001801368700002301386700002401409700002001433700001701453856013001470       2011                        eng d00aZn(II)-cyclam based chromogenic sensors for recognition of atp in aqueous solution under physiological conditions and their application as viable staining agents for microorganism0 aZnIIcyclam based chromogenic sensors for recognition of atp in a  cMAR  a4162–41700 v503 a<p>Two chromogenic complexes, L.Zn (where L is (E)-4-((4-(1,4,8,11-tetraazacyclotetradecan-1-ylsulfonyl)phenyl)diazenyl)-N,N-dimethylaniline) and its [2]pseudorotaxane form (α-CD.L.Zn), were found to bind preferentially to adenosine triphosphate (ATP), among all other common anions and biologically important phosphate (AMP, ADP, pyrophosphate, and phosphate) ions in aqueous HEPES buffer medium of pH 7.2. Studies with live cell cultures of prokaryotic microbes revealed that binding of these two reagents to intercellular ATP, produced in situ, could be used in delineating the Gram-positive and the Gram-negative bacteria. More importantly, these dyes were found to be nontoxic to living microbes (eukaryotes and prokaryotes) and could be used for studying the cell growth dynamics. Binding to these two viable staining agents to intercellular ATP was also confirmed by spectroscopic studies on cell growth in the presence of different respiratory inhibitors that influence the intercellular ATP generation.</p>1 aMahato, Prasenjit1 aGhosh, Amrita1 aMishra, Sanjiv, K.1 aShrivastav, Anupama1 aMishra, Sandhya1 aDas, Amitava  uhttps://library.ncl.res.in/content/znii-cyclam-based-chromogenic-sensors-recognition-atp-aqueous-solution-under-physiological02275nas 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-metallosurfactants00937nas a2200181   4500008004100000245013400041210006900175260000800244300001400252490000700266520026000273100001700533700002200550700001800572700002100590700001700611856012700628       2012                        eng d00aInterrupted PET coupled TBET process for the design of a specific receptor for Hg2+ and its intracellular detection in MCF7 cells0 aInterrupted PET coupled TBET process for the design of a specifi  cJUL  a9293-92950 v483 a<p>A new coumarin–rhodamine conjugate constitutes a unique example of the interrupted PET coupled TBET response for developing an imaging reagent for determining the intracellular distribution of Hg2+ in MCF7 cells exposed to [Hg2+] as low as 2 ppb.</p>1 aSaha, Sukdeb1 aMahato, Prasenjit1 aBaidya, Mithu1 aGhosh, Sudip, K.1 aDas, Amitava  uhttps://library.ncl.res.in/content/interrupted-pet-coupled-tbet-process-design-specific-receptor-hg2-and-its-intracellular01981nas a2200157   4500008004100000245017200041210006900213260000800282300001800290490000800308520132800316100002201644700001701666700001701683856012301700       2012                        eng d00aRare example of TICT based optical responses for the specific recognition of Cr3+ by a 2,2?:6?,2?-terpyridine derivative and demonstration of multiple logic operations0 aRare example of TICT based optical responses for the specific re  cJUL  a17448–174570 v1163 a<p>Chemosensor L showed a nonlinear fluorescence response on specific binding to Cr3+ ion in the presence of various alkali, alkaline-earth, transition, and lanthanide metal ions. A luminescence band with maxima at 512 nm for L was observed (λext = 330 nm) for a twisted intramolecular charge transfer (TICT) transition following antienergy gap law behavior. However, normal energy gap law behavior prevailed on formation of a new nonluminescent charge transfer complex, Mn+·L. For paramagnetic metal ions, paramagnetism induced luminescence quenching could have also contributed to this. A new switched on fluorescence response at λems of 356 nm (λext of 330 nm) was observed due to Franck–Condon charge transfer (FC-CT) transition only on the formation of a complex, (Cr3+)2·L. Spectral studies revealed a unique dynamic coordination behavior and migration of Cr3+ from the terpyridyl fragment to the NNMe2 center of L as a function of the varying concentration of another ion (Zn2+) and the subtle difference in the binding affinities of the terpyridyl moiety toward Cr3+ and Zn2+. Further, spectral responses of L toward Zn2+, different concentration of Cr3+, H+ and on subsequent addition of F– as different ionic inputs could be correlated well for demonstrating various basic and combinatorial circuits.</p>1 aMahato, Prasenjit1 aSaha, Sukdeb1 aDas, Amitava  uhttps://library.ncl.res.in/content/rare-example-tict-based-optical-responses-specific-recognition-cr3-2262-terpyridine01765nas a2200229   4500008004100000245009600041210006900137260000800206300001600214490000700230520098300237100002201220700001701242700001501259700001901274700002801293700002701321700002601348700002301374700001701397856012101414       2012                        eng d00aRatiometric detection of Cr3+ and Hg2+ by a naphthalimide-rhodamine based fluorescent probe0 aRatiometric detection of Cr3 and Hg2 by a naphthalimiderhodamine  cJAN  a1769–17770 v513 a<p>Newly synthesized rhodamine derivatives, L1 and L2, are found to bind specifically to Hg2+ or Cr3+ in presence of large excess of other competing ions with associated changes in their optical and fluorescence spectral behavior. These spectral changes are significant enough in the visible region of the spectrum and thus, allow the visual detection. For L1, the detection limit is even lower than the permissible [Cr3+] or [Hg2+] in drinking water as per standard U.S. EPA norms; while the receptor, L2 could be used as a ratiometric sensor for detection of Cr3+ and Hg2+ based on the resonance energy transfer (RET) process involving the donor naphthalimide and the acceptor Cr3+/Hg2+-bound xanthene fragment. Studies reveal that these two reagents could be used for recognition and sensing of Hg2+/Cr3+. Further, confocal laser microscopic studies confirmed that the reagent L2 could also be used as an imaging probe for detection of uptake of these ions in A431 cells.</p>1 aMahato, Prasenjit1 aSaha, Sukdeb1 aSuresh, E.1 aDi Liddo, Rosa1 aParnigotto, Pier, Paolo1 aConconi, Maria, Teresa1 aKesharwani, Manoj, K.1 aGanguly, Bishwajit1 aDas, Amitava  uhttps://library.ncl.res.in/content/ratiometric-detection-cr3-and-hg2-naphthalimide-rhodamine-based-fluorescent-probe01954nas a2200217   4500008004100000245014700041210006900188260000800257300001400265490000700279520116100286100001701447700002201464700002301486700001501509700002501524700001801549700002101567700001701588856013101605       2012                        eng d00aRecognition of Hg 2+ and Cr 3+ in physiological conditions by a rhodamine derivative and its application as a reagent for cell-imaging studies0 aRecognition of Hg 2 and Cr 3 in physiological conditions by a rh  cDEC  a336–3450 v513 a<p>A new rhodamine-based receptor, derivatized with an additional fluorophore (quinoline), was synthesized for selective recognition of Hg2+ and Cr3+ in an acetonitrile/HEPES buffer medium of pH 7.3. This reagent could be used as a dual probe and allowed detection of these two ions by monitoring changes in absorption and the fluorescence spectral pattern. In both instances, the extent of the changes was significant enough to allow visual detection. More importantly, the receptor molecule could be used as an imaging reagent for detection of Hg2+ and Cr3+ uptake in live human cancer cells (MCF7) using laser confocal microscopic studies. Unlike Hg(ClO4)2 or Hg(NO3)2 salts, HgCl2 or HgI2 failed to induce any visually detectable change in color or fluorescence upon interaction with L1 under identical experimental conditions. Presumably, the higher covalent nature of HgII in HgCl2 or HgI2 accounts for its lower acidity and its inability to open up the spirolactam ring of the reagent L1. The issue has been addressed on the basis of the single-crystal X-ray structures of L1·HgX2 (X– = Cl– or I–) and results from other spectral studies.</p>1 aSaha, Sukdeb1 aMahato, Prasenjit1 aReddy, Upendar, G.1 aSuresh, E.1 aChakrabarty, Arindam1 aBaidya, Mithu1 aGhosh, Sudip, K.1 aDas, Amitava  uhttps://library.ncl.res.in/content/recognition-hg-2-and-cr-3-physiological-conditions-rhodamine-derivative-and-its-application00902nas a2200193   4500008004100000245013700041210006900178260000800247300001400255490000700269520018100276100001700457700002500474700002200499700001600521700002200537700001700559856013200576       2012                        eng d00aRhodamine-alginate conjugate as self-indicating gel beads for efficient detection and scavenging of Hg 2+ and Cr 3+ in aqueous media0 aRhodaminealginate conjugate as selfindicating gel beads for effi  cNOV  a1659-16610 v483 a<p>Effective extraction of Hg2+ and Cr3+ ions from aqueous media by novel rhodamine–alginate polymer-based highly fluorogenic, as well as colorimetric, chemosensor beads.</p>1 aSaha, Sukdeb1 aChhatbar, Mahesh, U.1 aMahato, Prasenjit1 aPraveen, L.1 aSiddhanta, A., K.1 aDas, Amitava  uhttps://library.ncl.res.in/content/rhodamine-alginate-conjugate-self-indicating-gel-beads-efficient-detection-and-scavenging-hg02211nas a2200181   4500008004100000245012700041210006900168260000800237300001600245490000700261520153200268100002401800700001801824700002201842700002001864700001701884856012801901       2012                        eng d00aTaco complex derived from a bis-crown ether capable of executing molecular logic operation through reversible complexation0 aTaco complex derived from a biscrown ether capable of executing   cJUL  a6789–68000 v773 a<p>As learned from natural systems, self-assembly and self-sorting help in interconnecting different molecular logic gates and thus achieve high-level logic functions. In this context, demonstration of important logic operations using changes in optical responses due to the formation of molecular assemblies is even more desirable for the construction of a molecular computer. Synthesis of an appropriate divalent as well as a luminescent crown ether based host 1 and paraquat derivatives, 2(PF6)2 and 3(PF6)2, as guests helped in demonstrating a reversible [3](taco complex) (1·{2(PF6)2}2 or 1·{3(PF6)2}2) formation in nonpolar solvent. Detailed 1H NMR studies revealed that two paraquat units were bound cooperatively by the two crown units in 1. Because of preorganization, the flexible host molecule 1 adopts a folded conformation, where each of two paraquat units remain sandwiched between the two aromatic units of each folded crown ether moiety in 1. Disassembly of the “taco” complex in the presence of KPF6 and reassembly on subsequent addition of DB18C6 was initially demonstrated by 1H NMR spectral studies, which were subsequently corroborated through luminescence spectral studies. Further, luminescence spectral responses as output signals with appropriate and two independent molecular inputs could be correlated to demonstrate basic logic operation like OR and YES gates, while the results of the three molecular inputs could be utilized to demonstrate important logic operation like an INHIBIT gate.</p>1 aMandal, Amal, Kumar1 aDas, Priyadip1 aMahato, Prasenjit1 aAcharya, Suhash1 aDas, Amitava  uhttps://library.ncl.res.in/content/taco-complex-derived-bis-crown-ether-capable-executing-molecular-logic-operation-through02568nas a2200193   4500008004100000022001400041245006000055210005900115260011000174300001600284490000600300520188500306100002202191700001702213700001802230700002302248700001702271856008602288       2014                        eng d  a2046-206900aOverview of the recent developments on Hg2+ recognition0 aOverview of the recent developments on Hg2 recognition  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUN  a36140-361740 v43 a<p>Adverse influences of mercury on living organisms are well known. Despite efforts from various regulatory agencies, the build-up of Hg2+ concentration in the environment is of serious concern. This necessitates the search for new and efficient reagents for recognition and detection of Hg2+ in environmental samples as well as for application in diagnostics. Among various detection processes adopted for designing such reagents, generally methodologies that allow associated changes in spectra properties are preferred for the obvious ease in the detection process. Significant changes in the electronic spectral pattern in the visible region of the spectrum also induce detectable changes in solution colour for naked-eye detection and are useful for developing reagents for in-field sample analysis with yes-no type binary responses. However, reagents that allow detection of Hg2+ with associated fluorescence on response are useful for detection of Hg2+ in environmental samples, as well as for use as an imaging reagent, for detection of cellular uptake. High spin-orbit coupling constant for Hg2+ along with its high solvation energy in aqueous medium poses a challenge in developing efficient reagents with fluorescence on response that work in aqueous medium/physiological condition. To get around this problem, several methodologies, like conversion of rhodamine derivative spirolactam to strongly fluorescent xanthenes that form on binding to Hg2+, chemodosimetric reaction for generation of a new luminescent derivative, have been adopted. Apart from these, modified charge transfer processes on binding to Hg2+ have also been utilized for designing reagents for optical detection of Hg2+. Immobilization of such reagents on solid surfaces also led to the development of self-indicating Hg2+ ion scavengers. All such examples are discussed in the present review.</p>1 aMahato, Prasenjit1 aSaha, Sukdeb1 aDas, Priyadip1 aAgarwalla, Hridesh1 aDas, Amitava  uhttps://library.ncl.res.in/content/overview-recent-developments-hg2-recognition-0