Molecular linkers

J. A. Larsson, M. Nolan, and J. C. Greer, Interations between thiol molecular linkers and the Aul3 nanoparticle, J. Phys. Chem. B 106, 5931-5837 (2002). 

Upon reacting SWCNT-acyl chlorides with a,co-diamines such as tripropylene-tetramine as molecular linker and subsequent diamide formation with another SWCNT, Roth and coworkers [109, 110] and Kiricsi et al. [Ill] succeeded in the interconnection of tubes and the formation of carbon nanotube junctions. End-to-end (Scheme 1.6a) and end-to-side nanotube interconnections (Scheme 1.6b) were formed and observed by AFM. Statistical analyses of the AFM images showed around 30% junctions in functionalized material [42],... 

Scheme 1.20 PEG-tethered SWCNTs and interconnections between individual SWCNTs through cycloaddition of a,copolyethylene glycol dinitrenes as the molecular linker.

Tethered SWCNTs and interconnections between individual SWCNTs using a,to-dinitrenes as the molecular linker (Scheme 1.20) were reported the first time in 2003 by Holzinger et al. [157]. The bisnitrenes were derived from thermolysis of polyethylene glycol) PEG 600 bisazidocarbonate the covalent linkage was characterized by SEM studies, XPS, X-ray diffractograms and Raman spectra [157]. 

Vlckova et al. demonstrated single-molecule SERS in self-assembled dimers of silver nanoparticles [161]. The self-assembly process was driven by nanoparticle functionalization with a bifunctional molecular linker (4,4 -diaminoazobenzene) which forms a molecular bridge between the particles. Molecules forming the molecular bridge are then precisely positioned within the hot spot with the molecular population being controlled by careful optimization of the linker to... 

AuNPs inserted between the electrode surface and redox metalloproteins therefore both work as effective molecular linkers and exert eflfident electrocatalysis. Recent considerations based on resonance turmeling between the electrode and the molecule via the AuNP as a mechanism for enhanced interfadal ET rates suggest that electronic spillover rather than energetic resonance is a hkely origin of the effects (J. Kleis et al., work in progress). Even slightly enhanced spillover compared with a planar Au(lll) surface is enough to enhance the ET rate by the observed amount over a 10-15 A ET distance. 

A typical experimental setup is sketched in Scheme 5. Organic precursor layers are deposited on the atomically clean surfaces by sublimation of the molecular linkers, typically present in high-purity powder form. The temperature of the substrate is controllably varied from cryogenic conditions ( 10 K) to elevated temperatures ( 500K) in order to achieve thermodynamically metastable or equilibrated products. In the surface-assembled systems the coordination centers are evaporated using electron beam or re-... 

Also, the threefold coordination of the Co centers in the dicarbonitrile nanomeshes described above could be rationalized with the help of DFT calculations. For the modeling, the molecular linkers were simplified as NC-Phi-CN refaining the carbonitrile endgroups that interact with the Co centers. In addition, the molecules were confined in a plane in accordance with the STM data, showing that the aromatic polyphenylene linkers are ad-... 

Photoelectrodes, consisting of CdS nanocrystals that are directly attached to an electrode (gold or conducting oxide) or indirectly via a dithiol molecular linker have been studied extensively [19, 20, 116-120]. Here, we will focus on work that demonstrates the power of small-amplitude methods in photoelectrochemical characterization [26, 123, 124]. By measuring the photoelectrochemical activity of gold/Q-CdS electrodes, as the potential of the gold electrode was varied, it could be concluded that photoinduced electron transfer between the gold surface... 

Zahn S, Frank R, Hey-Hawkins E, Kirchner B (2011) Pnicogen bonds a new molecular linker Chem Eur J 17 6034-6038... 

If large organic molecules (proteins etc.) must be immobiUzed, the primary problem is to synthesize the molecular linker responsible for ensuring a stable bond with the sensor surface. Common linkers are e.g. groups such as the following ... 

San Diego, CA, COMP 50. Exhaustive Search for Molecular Linkers in Structure-Based Drug Design. 

Fig. 8.21 Variation of log with -ArG for a series of compounds with the structures given in (2). Kinetic measurements were conducted in 2-methyltetrahydrofuran at 296 K. The distance between the donor (the reduced biphenyl group) and the acceptor is constant for all compounds in the series because the molecular linker remains the same. Each acceptor has a characteristic standard potential, so it follows that the standard Gibbs energy for the electron transfer process is different for each compound in the series. The line is a fit to a version of eqn 8.32 the maximum of the parabola occurs at -A G = A = 1.2 eV =...

Gohy, J.-F., Lohmeijer, B.G.G., Alexeev, A. et al. (2004) Cylindrical micelles from the aqueous self-assembly of an amphiphilic poly(ethylene oxide)-b-poly(fenocenylsilane) (PEO-b-PFS) block copolymer with a metallo-supra-molecular linker at the block junction. Chemistry - A European Journal, 10,4315. 

Huang A, Caro J. Facile synthesis of LTA molecular sieve membranes on covalently functionalized supports by using diisocyanates as molecular linker. J Mater Chem 2011 21 11424—9. 

The question arises about the best way of connecting dendrimers - van der Waals, ionic, covalent or molecular linkers. Currently, efforts are being made to decide which is the best possible architecture. 

The chains contained from 3 to 20 NPs (Figure 7(d)). The low fraction of branched chains and the absence of 3D aggregates were indicative of selective functionalization of the NPs at the opposite poles or at least, a much higher reaction rate between the ligands localized at the poles than at the deferts in the ligand shell in other locations. In the chains, the inter-partide distance (defined as the two nearest points between adjacent NPs) correlated with the length of molecular linkers. 

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