02692nas a2200265   4500008004100000022001400041245009300055210006900148260000800217300001400225490000800239520180600247100003102053700002702084700002202111700001802133700002202151700002202173700002002195700002002215700002702235700002402262700002002286856012002306       2020                        eng d  a1932-744700aLigand structure directed dimensionality reduction (2D -> 1D) in lead bromide perovskite0 aLigand structure directed dimensionality reduction 2D 1D in lead  cJAN  a1888-18970 v1243 a<p>Low dimensional (2D, 1D) lead halide perovskites are currently attracting huge research interest due to their enabling properties. Demonstrating synthetic control on the dimensionality/ structure of these perovskites is highly challenging. Dimensionality in these perovskites is largely dictated by the nature/structure and composition of the incorporating ligands and the utilized synthetic conditions. Here, we demonstrate chemical composition based control on reduction of dimensionality (2D -&gt; 1D) for lead bromide perovskite utilizing 2-(2-aminoethyl)isothiourea dihydrobromide as a common precursor ligand (Isothio Bromide). Controlling the hydrothermal reaction parameters (temperature, time) at a fixed precursor ratio affords corner-shared, contorted 2D sheet perovskite and corner-shared, contorted, chiral 1D chain perovskite. Such dimensionality reduction leads to contrasting photophysical properties: 1D chain perovskite shows long-lived and self-trapped broad band emission, whereas 2D perovskite shows short-lived, band edge emission with a long tail. Mechanistic studies and single crystal structure analysis reveal the incorporation of the utilized precursor ligand (Isothio Bromide) in 2D perovskite. Surprisingly, the 1D perovskite is found to be chiral (P2(1) space group) incorporating 2-(2-aminoethyldisulfanyl)ethanamine and ammonium ions as the achiral ligands generated in situ due to hydrothermal cleavage of the precursor (Isothio Bromide) ligand. Such structural and compositional change of the ligands, which manifests a different hydrogen bonding network in the resultant perovskite structure, plays a decisive role in dictating the final molecular formula and dimensionality/structure of the perovskite which largely controls their photophysical properties.</p>
1 aBakthavatsalam, Rangarajan1 aHaris, Muhammed, P. U.1 aShaikh, Samir, R.1 aLohar, Amruta1 aMohanty, Ashutosh1 aMoghe, Dhanashree1 aSharma, Shivani1 aBiswas, Chinmoy1 aRaavi, Sai, Santhosh K1 aGonnade, Rajesh, G.1 aKundu, Janardan  uhttps://library.ncl.res.in/content/ligand-structure-directed-dimensionality-reduction-2d-1d-lead-bromide-perovskite02039nas a2200229   4500008004100000022001400041245013300055210006900188260000900257300001400266490000600280520121500286100001901501700003101520700001701551700002001568700002401588700002701612700002401639700002001663856012601683       2021                        eng d  a2050-752600aLead-free zero dimensional tellurium(iv) chloride-organic hybrid with strong room temperature emission as a luminescent material0 aLeadfree zero dimensional telluriumiv chlorideorganic hybrid wit  cMAR   a4351-43580 v93 a<p>Despite the current progress in `Pb-free' low dimensional main group metal halide based luminescent materials, it is challenging to synthesize Te(iv) halide hybrids with strong ambient emission with excitation features in the visible range as efficient and stable phosphors for potential lighting applications. Reported here is a (benzyltriethylammonium)(2)TeCl6 zero dimensional hybrid material with excitation features in the visible range and strong room temperature, broadband, intrinsic luminescence (PLQY similar to 15%) arising due to self-trapped excitons (STEs). Furthermore, a proof-of-concept LED architecture demonstrates successful optical down-conversion with a visible light excitation source. Here, exclusive adoption of a `regular' octahedral Te(iv)-halide unit structure with minimal static distortion provides a unique opportunity to unmask the role played by 5s(2) lone pair electrons in shaping the emissive properties. This effort may open up new avenues towards unravelling the role of lone pair stereoactivity in controlling the PLQY in low dimensional hybrids that has proven to be challenging for the reported (Sb, Sn) based low dimensional 5s(2) metal halide hybrid materials.</p>1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aBahadur, Vir1 aBiswas, Chinmoy1 aMali, Bhupendra, P.1 aRaavi, Sai, Santosh Ku1 aGonnade, Rajesh, G.1 aKundu, Janardan  uhttps://library.ncl.res.in/content/lead-free-zero-dimensional-telluriumiv-chloride-organic-hybrid-strong-room-temperature02548nas a2200229   4500008004100000022001400041245016300055210006900218260000900287300001200296490000600308520169200314100001902006700003102025700002402056700001702080700002002097700002702117700002402144700002002168856013002188       2021                        eng d  a2050-752600aMetal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony(iii) halide hybrids0 aMetal halide structure and the extent of distortion control the   cJAN   a348-3580 v93 a<p>Antimony(iii) halide based zero dimensional hybrids have gained attention as broadband emitters. Until now, quadrangular pyramidal SbX5 based and octahedral SbX6 based 0D hybrids have been reported utilizing different organic ligands demonstrating some structural tunability affecting their emissive properties. Utilizing a common organic ligand, here we demonstrate the structural tunability (quadrangular pyramidal, octahedral, or a combination thereof) of the metal halide unit in Sb(iii)Cl 0D hybrids with contrasting photo-physical properties (broadband, Stokes shift, strong/weak colored emission). The structure-property-mechanism correlation of the synthesized compounds [1 (C12H52Cl18N8O4Sb3; tris Sb green); 2 (C12H50Cl14N8O3Sb2; tris Sb red); 3 (C24H88Cl25N16O4Sb3; tris Sb yellow)] identifies crucial factors that control their emissive properties. The X-ray analysis reveals the structure (1-octahedral; 2-quadrangular pyramidal; 3-combination thereof) and the order of the extent of structural distortion as 1-3 MUCH LESS-THAN 2. The metal halide coordination environment asymmetry and its structure are observed to dictate PL emission energy (1-green; 2-red; 3-yellow) as supported by a qualitative Molecular Orbital scheme. The extent of structural distortion guides the observed Stokes shifts (1-165 nm; 2-290 nm; 3-200 nm; 1-3 &lt; 2). Interestingly, the extent of distortion is found to be well correlated with the observed PLQY (1-45%; 2-6%; 3-43%; 1-3 &gt;&gt; 2). This report clearly demonstrates the structural tunability and the effect of the metal halide unit structure/distortion in shaping the emissive properties of 0D organic Sb(iii) halide hybrids.</p>
1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aMali, Bhupendra, P.1 aBahadur, Vir1 aBiswas, Chinmoy1 aRaavi, Sai, Santosh Ku1 aGonnade, Rajesh, G.1 aKundu, Janardan  uhttps://library.ncl.res.in/content/metal-halide-structure-and-extent-distortion-control-photo-physical-properties-luminescent02784nas a2200289   4500008004100000022001400041245016800055210006900223260000900292300001200301490000700313520176900320100001902089700003102108700001802139700001602157700002402173700002002197700002102217700002002238700002702258700002402285700002402309700001902333700002002352856012202372       2021                        eng d  a2050-752600aSynergistic electronic coupling/cross-talk between the isolated metal halide units of zero dimensional heterometallic (Sb, Mn) halide hybrid with enhanced emission0 aSynergistic electronic couplingcrosstalk between the isolated me  cDEC   a360-3700 v103 aHeterometallic 0D metal halide hybrids, consisting of more than one kind of metal halide units, are anticipated to manifest synergistic effects on the photo-physical properties of the constituent metal halide units. Such architectures hold great promise for design and development of function-targeted materials. However, heterometallic 0D hybrids, featuring isolated metal halide units, typically do not show any synergistic effects due to large inter-unit spatial separations that inhibit interactions/coupling between the constituent metal halide units. It remains challenging to design synthetic strategies that would support structural modifications to allow synergistic electronic coupling between the metal halide units in heterometallic 0D hybrids. Here, we report synthesis and characterization of heterometallic (Sb, Mn) 0D hybrid, namely Tris SbMnCl, with isolated MnCl5 units, (Sb/Mn)Cl-6 units, dispersed in the organic ligand matrix and layer of dynamic and networked water molecules. Steady state and time resolved emission spectra (TRES) analysis suggests strong synergistic interaction between the isolated metal halide units. Efficient energy transfer from the strongly absorbing Sb centres to emissive Mn centres results in the observed enhanced emission. Proton conductivity measurements together with first-principles calculations suggest the unique role of the networked water molecules in mediating the electronic coupling/energy transfer between the separated metal halide units in Tris SbMnCl hybrid. This report highlights the role of structure/composition of the synthesized heterometallic 0D hybrid in attaining electronic dimensionality higher than 0D through synergistic electronic interaction between the isolated metal halide units.1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aDas, Deep, K.1 aSam, Jisvin1 aMali, Bhupendra, P.1 aBiswas, Chinmoy1 aMaana, Narugopal1 aThomson, Stuart1 aRaavi, Sai, Santosh Ku1 aKurungot, Sreekumar1 aGonnade, Rajesh, G.1 aDutta, Sudipta1 aKundu, Janardan  uhttps://library.ncl.res.in/content/synergistic-electronic-couplingcross-talk-between-isolated-metal-halide-units-zero