A series of neutral, platinum-based macrocycles was synthesized from rigid oxygen donor building blocks via self-assembly. The combination of a platinum-based 60 degrees acceptor unit 1 with several linear and angular dicarboxylate bridging ligands afforded hitherto unknown neutral platinum-based supramolecular triangles and rhomboids. In addition, a similar reaction of the diplatinum molecular clip 6 and three different linear dicarboxylates led to the formation of neutral molecular rectangles. Most of the macrocycles were characterized by X-ray single-crystal structure analysis, and, in all cases, NMR spectra were consistent with the formation of single highly symmetrical species.

The design and self-assembly of novel cavity-cored metallodendrimers via noncovalent interactions are described. By employing [G0]-[G3] 120 degrees ditopic donor linkers substituted with Fréchet-type dendrons and appropriate rigid di-Pt(II) acceptor subunits, [G0]-[G3]-rhomboidal metallodendrimers and [G0]-[G3]-hexagonal, "snowflake-shaped" metallodendrimers with well-defined shape and size were prepared under mild conditions in high yields. The assemblies were characterized with multinuclear NMR ((1)H and (31)P), mass spectrometry (ESI-MS and ESI-FT-ICR-MS), and elemental analysis. Isotopically resolved mass spectrometry data support the existence of the metallodendrimers with rhomboidal and hexagonal cavities, and NMR data are consistent with the formation of all ensembles. The structures of [G0]- and [G1]-rhomboidal metallodendrimers were unambiguously confirmed via single-crystal X-ray crystallography. The shape and size of two [G3]-hexagonal metallodendrimers were investigated with MM2 force-field modeling.

The syntheses, characterizations, and biological activities of three organoplatinum compounds, each containing a triazole ring, are discussed. These organometallic compounds demonstrate superior cytotoxicity against osteosarcoma and human breast cancer cells relative to cisplatin, a well-known chemotherapeutic agent used for chemotherapy.

The well-known azo coupling reaction was utilized to yield a new group of triptycene-derived azo polymers (TAPs) bearing phloroglucinol units. TAPs have hierarchical porosity (presence of micropores and mesopores) and are thermally stable. TAPs have moderate surface area (SABET up to 772 m2 g–1) but demonstrate rather high CO2 uptake (up to 150 mg g–1). Azo functional group is reportedly N2-phobic and hence porous organic polymers (POPs) with azo (−NN−) units show high CO2/N2 selectivity. TAPs register CO2/N2 selectivity (273 K) that is higher than most azo-POPs reported until date. This favorable property of TAPs is attributed to the simultaneous coexistence of triptycenes (aromatic and three-dimensional rigid with high internal free volume), phenolic-OH (polar and CO2-philic), and azo (CO2-philic and N2-phobic) functional groups in the polymeric framework.

Two Pt(4)-Fe(2) mixed-metal neutral assemblies, 4 and 5, incorporating four bis(triethylphosphine)platinum(II) centers, two flexible bridging 1,1'-ferrocenedicarboxylates, and two rigid 2,9-phenanthrenediyl (4) or 1,8-anthracenediyl (5) bridges, have been synthesized. X-ray characterization of 4 and 5 reveals the formation of discrete and highly symmetrical heterobimetallic neutral species possessing a rhomboidal and rectangular shape, respectively. The rectangular molecules, 5, could be reversibly oxidized in two two-electron steps, separated by 0.21 V. Spectroelectrochemistry in the UV-vis-NIR region confirms the ferrocene groups as primary oxidation sites; however, the intermediate 5(2+) is EPR silent even at 4 K due to enhanced EPR relaxation involving the oxidizable 1,8-anthracenediyl linkers.

The single-molecule fluorescence microscopy imaging of indiVidual palladium(II) complexes is reported and the requisite high-quantum-yield BODIPY fluorophore tags are synthesized and shown to act as spectators when bound to metal complexes. These combined experimental results lay the fundamental groundwork for studying organometallic reaction chemistry at the single-molecule leVel using fluorophore tags.

Self-recognition in the transition-metal-mediated self-assembly of some 2-D polygons is presented. Prolonged heating of two or three organoplatinum reagents with 4,4'-dipyridyl in aqueous acetone results in the predominant formation of a rectangle, triangle, and/or square. All mixtures are characterized with NMR and electrospray ionization mass spectrometry (ESIMS). Despite the potential for ill-defined oligomeric products, these mixed ligand systems prefer to self-assemble into discrete species.

Herein, facile synthesis and characterization of four Triazole linked Network Polymers (TNPs) in high yields is described. These nitrogen rich polymers are derived using "Click" reaction between 2,6,14triazido triptycene and various di or triethynyl comonomers. The TNPs are microporous and exhibit high surface area (SA BET up to 1348 m 2 g −1 ). Due to incorporation of 1,2,3-triazole motif (a CO 2 -philic moiety), the TNPs record moderate to high CO 2 uptake (upto 4.45 mmol/g at 273K and 1 bar). The TNPs also show very good CO 2 /N 2 (upto 48) and CO 2 /CH 4 (8 -9) selectivity. While highest storage capacity has been registered by TNP4 (CO 2 4.45 mmol/g at 273K and 1 bar, CH 4 23.8 mg/g, H 2 1.8 wt%), the highest CO 2 /N 2 and CO 2 /CH 4 selectivity was shown by TNP3 which contains additional nitrogen rich building blocks in the form of heteroaromatic pyrazine rings. These results suggest that TNPs are porous materials with potential practical application in gas storage and separation. Introduction:Design and syntheses of porous materials have attracted considerable research attention over the past decade. 1-4 In recent years, research output in this direction has witnessed considerable growth. 5-13 Depending on the pore size, porous materials may be classified as ultra-microporous 14-16 microporous, 12,13 mesoporous 17-19 or macroporous. 20,21 Among these, microporous materials have emerged as potential candidates for applications that include but are not limited to gas storage and separation. Microporous materials, such as zeolites 22,23 and metal-organic frameworks (MOFs), 1-5 contain metal atoms. Alternatively, microporous materials can also be designed in the form of metal-free organic polymers that are highly crosslinked. Acronyms such as COFs, CMPs, CTFs, EOFs, HCPs, MOPs, OCFs, PAFs, PIMs, POFs, POPs, PPFs, PPNs, etc have been coined to describe metal-free porous organic polymers. 6-13 In general, MOFs have limited industrial applications as porous materials because presence of relatively labile coordination bonds that lower their thermal stability. 24 On the other hand, in microporous organic polymers (MOPs), light weight elements (such as H, C, N, and O) are interlinked via relatively stronger covalent bonds. Therefore these metal-free materials have lesser mass densities and higher stabilities (chemical and thermal). In addition, MOPs can be easily tailored with respect to properties such as guest selectivity and pore properties, due to availability of a plethora of multifunctional organic molecules that can serve as monomers towards the syntheses of MOPs.In contemporary research dealing with development of microporous materials, design of MOPs for selective CO 2 capture and sequestration has received special attention. This has stemmed from environmental and energy concerns related to CO 2 , which is a major greenhouse gas. It is well known that thermal power plants emitting flue gas (containing approximately 15 % CO 2 ) are a major contributor to anthropogenic CO 2 . Therefore, in order to contain g...