Dalton Transactions

doi: 10.1039/c7dt90084hpmid: N/A

doi: 10.1039/C7DT90084Hpmid: N/A

doi: 10.1039/C7DT90085Fpmid: N/A

doi: 10.1039/c7dt90085fpmid: N/A

doi: 10.1039/c7dt90086dpmid: N/A

doi: 10.1039/C7DT90086Dpmid: N/A

Bharadwaj, Parimal K.

doi: 10.1039/c7dt00722apmid: 28436497

Macrobicyclic cryptands incorporating amine groups along with oxygen donors that are laterally non-symmetric constitute an important class of organic compounds. These molecules can form inclusion complexes with different transition and main group metal ions. It is also possible to modify the binding characteristics of these compounds through attachment of different groups. Some of these metal complexes can be useful homogeneous catalysts in different organic transformations. If there are chiral centers present in the cryptands, they can be useful in asymmetric syntheses. The three secondary amine groups present in the bridges can be partially or completely derivatized with different fluorophores for fluorescence signaling of transition, inner-transition and heavy metal ions. It is also possible to sequentially attach different fluorophores to study single- as well as multi-step Förster resonance energy transfer. Different donor/acceptor groups can be attached to study second and third order optical nonlinearity. The present article describes several aspects of the chemistry of laterally non-symmetric cryptands and provides future directions for research in this area.

Ji, Peng; Lu, Kun; Lu, Xinqing; Xu, Hao; Wu, Peng

doi: 10.1039/c7dt00640cpmid: 28401221

Ti-SSZ-70 and Ti-ECNU-6, with identical intralayer structures but distinct interlayer connections, were prepared from similar synthetic gels free of alkali metal ions and boric acid. Ti-SSZ-70, composed of vertically misaligned MWW layers, was transferred to Ti-ECNU-6, structurally analogous to the Ti-MWW zeolite with a well-aligned layer stacking, upon the addition of an appropriate amount of hexamethyleneimine to the gel. These two titanosilicate catalysts exhibited outstanding catalytic activities in the liquid-phase alkene epoxidation.

Kaczmarek, A. M.; Liu, J.; Laforce, B.; Vincze, L.; Van Hecke, K.; Van Deun, R.

doi: 10.1039/c7dt01058cpmid: 28401979

Here, the excellent thermal sensing capability of a multinuclear lanthanide polyoxometalate in the cryogenic region (<100 K) is presented for the first time. Up till now, no lanthanide polyoxometalates have been studied for their use as ratiometric luminescent thermometers. The investigated Tb3+ polyoxometalate cluster is doped with 1.6% (P1) and 8.4% (P2) of Eu3+ ions. When excited into the Mo–O charge transfer bands, at room temperature only the emission of the Eu3+ ions is observed suggesting a very efficient energy transfer between Mo–O→Tb3+→Eu3+. Only in the cryogenic region the emission of Tb3+ is also witnessed.

Murata, Suguru; Takahashi, Kazuyuki; Mochida, Tomoyuki; Sakurai, Takahiro; Ohta, Hitoshi; Yamamoto, Takashi; Einaga, Yasuaki

doi: 10.1039/c7dt01030cpmid: 28406513

A novel neutral heteroleptic FeIII complex from two kinds of π-extended tridentate ligands was designed and prepared. The π-ligands formed a three-dimensional purely π-stacking interaction network. The present complex proved to be the first neutral spin-crossover (SCO) FeIII complex with a N3O3 coordination sphere exhibiting an abrupt SCO transition with a thermal hysteresis of 10 K and the light-induced excited spin-state trapping effect.