Self-Assembly of Discrete Cyclic Nanostructures Mediated by Transition Metals

The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

"United we stand, divided we fall."--Aesop. Aggregation-induced emission (AIE) refers to a photophysical phenomenon shown by a group of luminogenic materials that are non-emissive when they are dissolved in good solvents as molecules but become highly luminescent when they are clustered in poor solvents or solid state as aggregates. In this Review we summarize the recent progresses made in the area of AIE research. We conduct mechanistic analyses of the AIE processes, unify the restriction of intramolecular motions (RIM) as the main cause for the AIE effects, and derive RIM-based molecular engineering strategies for the design of new AIE luminogens (AIEgens). Typical examples of the newly developed AIEgens and their high-tech applications as optoelectronic materials, chemical sensors and biomedical probes are presented and discussed.

Aggregation-Induced Emission: The Whole Is More Brilliant than the Parts

The preparation, structure, and chemistry of hypervalent iodine compounds are reviewed with emphasis on their synthetic application. Compounds of iodine possess reactivity similar to that of transition metals, but have the advantage of environmental sustainability and efficient utilization of natural resources. These compounds are widely used in organic synthesis as selective oxidants and environmentally friendly reagents. Synthetic uses of hypervalent iodine reagents in halogenation reactions, various oxidations, rearrangements, aminations, C–C bond-forming reactions, and transition metal-catalyzed reactions are summarized and discussed. Recent discovery of hypervalent catalytic systems and recyclable reagents, and the development of new enantioselective reactions using chiral hypervalent iodine compounds represent a particularly important achievement in the field of hypervalent iodine chemistry. One of the goals of this Review is to attract the attention of the scientific community as to the benefits of...

Advances in Synthetic Applications of Hypervalent Iodine Compounds

Light-Emitting Self-Assembled Materials Based on d(8) and d(10) Transition Metal Complexes.

[Pt(bzq)Cl(CNR)] [bzq = benzoquinolinate; R = tert-butyl (tBu 1), 2-6-dimethylphenyl (Xyl 2), 2-naphthyl (2-Np 3)] complexes have been synthesized and structurally and photophysically characterized. 1 was found to co-crystallize in two distinct pseudopolymorphs: a red form, which exhibits an infinite 1D-chain ([1]∞) and a yellow form, which contains discrete dimers ([1]2), both stabilized by interplanar π···π (bzq) and short Pt···Pt bonding interactions. Complex 3, generated through the unexpected garnet-red double salt isomer [Pt(bzq)(CN-2-Np)2][Pt(bzq)Cl2] 4, crystallizes as yellow Pt···Pt dimers ([3]2), while 2 only forms π···π (bzq) contacting dimers. Their electronic absorption and luminescence behaviors have been investigated. According to Time-Dependent Density Functional Theory (TD-DFT) calculations, the lowest-lying absorption (CH2Cl2) has been attributed to combined 1ILCT and 1MLCT/1ML′CT (L = bzq, L′ = CNR) transitions, the latter increasing from 1 to 3. In solid state, while the yellow form [1...

Structural and Luminescence Studies on π···π and Pt···Pt Interactions in Mixed Chloro-Isocyanide Cyclometalated Platinum(II) Complexes†

Heteropolynuclear cycloplatinated complexes: Structural and photophysical properties

An overview of the chemistry of homo and heteropolynuclear platinum complexes containing bridging acetylide (μ-C≡CR) ligands

Synthesis and Luminescence of Cyclometalated Compounds with Nitrile and Isocyanide Ligands

The synthesis of a new series of heterocyclic mesogens, the trans-4-alkyloxy-4'-stilbazoles (CnH2n+1OC6H4CH=CHC5H4N), is described and the phase behaviour is reported for all homologues between methyloxy (C1) and dodecyloxy (C12). For n < 3, the compounds are non-mesomorphic; monotropic smectic phases are observed for n = 3 and 4, whilst homologues with n = 5 to 12 show enantiotropic smectic phases. For comparison the synthesis and properties of two trans-4-alkyloxy-stilbenes are also reported. The phases are assigned on the basis of either X-ray data or optical textures.

Elena Lalinde

Papers

Structural and Luminescence Studies on π···π and Pt···Pt Interactions in Mixed Chloro-Isocyanide Cyclometalated Platinum(II) Complexes†

Heteropolynuclear cycloplatinated complexes: Structural and photophysical properties

An overview of the chemistry of homo and heteropolynuclear platinum complexes containing bridging acetylide (μ-C≡CR) ligands

Synthesis and Luminescence of Cyclometalated Compounds with Nitrile and Isocyanide Ligands

4-Alkyloxy-4'-stilbazoles New heterocyclic mesogens