58791-49-4Relevant articles and documents
Elucidating the Growth of Metal-Organic Nanotubes Combining Isoreticular Synthesis with Liquid-Cell Transmission Electron Microscopy
Vailonis, Kristina M.,Gnanasekaran, Karthikeyan,Powers, Xian B.,Gianneschi, Nathan C.,Jenkins, David M.
, p. 10177 - 10182 (2019)
Metal-organic nanotubes (MONTs) are tunable porous 1D materials that are envisioned to be complementary to carbon nanotubes for anisotropic applications. To date, characterization of MONTs relies on single crystal X-ray diffraction (SCXRD) to determine structure and composition. This requires crystals on the micrometer regime, effectively rendering bulk 3D materials. By tracking the growth of a MONT as a function of time with liquid-cell transmission electron microscopy (LCTEM), TEM, and SCXRD, it was possible to ascertain that the material in the bulk phase matches the nanomaterial in terms of molecular structure. This result allowed for the first measurements of finite bundles of MONTs on the nanometer scale. By employing in situ LCTEM, a time course of the formation of small bundles of MONTs could be acquired which provided mechanistic information on MONT formation which is of utility in reaction optimization and applications development.
Quantification of Singlet Oxygen Generated by Thermolysis of 3,3'-(1,4-Naphthylidene)dipropionate. Monomol and Dimol Photoemission and the Effects of 1,4-Diazabicyclooctane
Di Mascio, Paolo,Sies, Helmut
, p. 2909 - 2914 (1989)
Singlet oxygen arising from the thermal decomposition of the water-soluble endoperoxide of 3,3'-(1,4-naphthylidene)dipropionate (NDPO2) or from hypochlorite/H2O2 was detected.Direct measurements of light emission due to the chemiluminescent transition of O2 (1δg)to the triplet ground state was monitored (a) by monomol emission in the near-infrared (1270 nm) with a liquid nitrogen cooled germanium diode and (b) by dimol emission in the visible spectral region (634 and 703 nm) with a red-sensitive photomultipler and photon counting.Chemical trapping of 1O2 generated by NDPO2 or by hypochlorite/H2O2 was used for quantification with the anthracene-9,10-diyldiethyl disulfate (EAS), yielding the endoperoxide (EASO2) as the specific oxidation product.The β value for EASO2 was calculated to be 7.7 x 1E-3 M and 8 x 1E-3 M when 1O2 was generated by NDPO2 or hypochlorite/H2O2, respectively.Due to the enhancement of the lifetime of 1O2, the β values were lower in D2O.The yields od 1O2 were measured, showing the one-half of the O2 liberated by thermolysis of NDPO2 was in the singlet state, whereas the yield for hypochlorite/H2O2 was near unity.The addition of 1,4-diazabicyclooctane (DABCO) increased dimol emission with a concomitant decrease of monomol light emission, but left the yield of EASO2 unchanged.Similar results were obtained with hypochlorite/H2O2.A calibration of the photoemission was performed, based on the 1O2 yield of NDPO2 thermodissociation.
Synthetic β-Cyclodextrin Dimers for Squaraine Binding: Effect of Host Architecture on Photophysical Properties, Aggregate Formation and Chemical Reactivity
Chaudhuri, Sauradip,Verderame, Molly,Mako, Teresa L.,Bandara, Y. M. Nuwan D. Y.,Fernando, Ashvin I.,Levine, Mindy
supporting information, p. 1964 - 1974 (2018/05/15)
Reported herein is the synthesis and application of three novel β-cyclodextrin dimer hosts for the complexation of near infrared (NIR) squaraine dyes in aqueous solution. A series of eight different N-substituted N-methyl anilino squaraine dyes with variable terminal groups are investigated, with an optimal n-hexyl-substituted squaraine guest demonstrating binding constants orders of magnitude higher than the other squaraine–host combinations and comparable to literature-reported systems. Moreover, hydrophobic complexation of the squaraine dyes with the β-cyclodextrin dimer hosts causes drastic changes in the squaraine's photophysical properties, propensity for aggregation and susceptibility to hydrolytic decay.
Secondary interactions in crystals of all ten isomers of Di(bromomethyl)naphthalene
Jones, Peter G.,Kus, Piotr
experimental part, p. 433 - 444 (2010/10/01)
The packing of all ten isomers of di(bromomethyl)naphthalene is analysed; nine of the structures were determined here, one (the 1,8-isomer) was already known. The 1,5- and 2,6-isomers display crystallographic inversion symmetry and the 2,7-isomer mirror symmetry through the central bond. For the 1,2-, 1,7- and 2,7-isomers, the bromomethyl groups point to the same side of the ring system, and for all other isomers to opposite sides. As expected, the molecules are linked into aggregates by various types of interactions: weak hydrogen bonds CH...Br, Br...Br interactions, CH...π contacts, π ...π stacking and Br...π contacts. The weak hydrogen bonds tend to be numerous but relativelyi; long, and do not combine to form readily recognisable patterns; a more readily assimilated view of the packing is based on the Br...Br interactions, which are observed for all isomers except 1,7 and 2,3, and in some cases lead to aggregation to form quadrilaterals or chains. With decreasing frequency, the interactions π ...π, C-H...π and Br...π are observed, but the latter are rare (just two examples) and very asymmetric, with contacts to only one or two carbons.
