Friday, August 10, 2007

Thrills, Chills, and Spills in Chemistry: An Enrapturing Blog Update

Today we've got a couple real barn-burners to tickle your fancy and light your lantern!

These bad boys are coming to you straight from the mean streets of the Journal of Materials Chemistry and Chemical Physics (read: don't mess with them!).

First up: Nanoparticles Gone Wild!


J. Mater. Chem., 2007, 17, 2695 - 2699, DOI: 10.1039/b702538f

Antibody conjugated magnetic PLGA nanoparticles for diagnosis and treatment of breast cancer

Jaemoon Yang, Choong-Hwan Lee, Joseph Park, Sungbaek Seo, Eun-Kyung Lim, Yong Jin Song, Jin-Suck Suh, Ho-Geun Yoon, Yong-Min Huh and Seungjoo Haam

DOX–magnetic PLGA nanoparticles conjugated with well-tailored antibodies were synthesized for the detection and therapy of breast cancer. Magnetic nanocrystals embedded in polymeric nanoparticles did not inhibit the nanoparticle formulation or drug release kinetics. The multimodal nanoparticles demonstrated remarkable cancer cell affinity and ultrasensitivity via magnetic resonance imaging. Furthermore, the loaded anticancer drugs were released and sustained for three weeks.


And next on the agenda is some quantum computing for our #1 reader, Schroedinger's Cat!


Chemical Physics
Vol: 336, Issue: 1, July 9, 2007

Title: Boolean and fuzzy logic implemented at the molecular level
Author: Gentili, P.L.
Keywords: Mamdani's and Sugeno's methods; Photochromism; Crisp logic; Fuzzy logic; Proximity effect
Abstract (English): In this work, it is shown how to implement both hard and soft computing by means of two structurally related heterocyclic compounds: flindersine (FL) and 6(5H)-phenanthridinone (PH). Since FL and PH have a carbonyl group in their molecular skeletons, they exhibit Proximity Effects in their photophysics. In other words, they have an emission power that can be modulated through external inputs such as temperature (T) and hydrogen-bonding donation (HBD) ability of solvents. This phenomenology can be exploited to implement both crisp and fuzzy logic. Fuzzy Logic Systems (FLSs) wherein the antecedents of the rules are connected through the AND operator, are built by both the Mamdani's and Sugeno's models. Finally, they are adopted as approximators of the proximity effect phenomenon and tested for their prediction capabilities. Moreover, FL as photochromic compound is also a multiply configurable crisp logic molecular element.
Publisher: Elsevier Science


Now for something completely different, grab your calculators and get your matrices ready, kids, because here comes some ab initio to finish up this action-packed update!


Chemical Physics Vol: 333, Issue: 2-3, March 30, 2007
pp. 201-207

Title: Ab initio study of the change from η-5- to η-1-coordination in group 12 dimetallocenes MM'(C5H5)2 with M, M'=Zn, Cd, Hg
Authors: Philpott, M.R.; Kawazoe, Y.
Keywords: Dimetallocene; Dizincocene; Zincous; Zn2^2^+; Cadmous; Cd2^2^+; Mercurous; Hg2^2^+; Quantum electronic structure; Density functional theory (DFT); Electronic structure; Electron localization function (ELF); Partial charge density; Kohn-Sham level; Zn2(η-1-C5H5)2; Zn2(η-5-C5H5)2
Abstract (English): For group 12 dimetallocenes, ab initio plane wave density functional theory (DFT) quantum electronic structure calculations predict that the metal atom can move from center η-5-C5H5 to edge η-1-C5H5 coordination with increase in atomic number. Systems studied include homo- and hetero-dimetallocene systems M2Cp2 and ZnMCp2 (where Cp=C5H5) in staggered and eclipsed initial configurations, and M is a group 12 atom Zn, Cd or Hg. The electronic change that drives the geometrical change is explored in calculations of the total charge density, partial charge densities of Kohn-Sham levels and the electron localization function (ELF). The zinc atoms prefer central η-5-C5H5 coordination, cadmium an off center position and mercury the edge displaced η-1-C5H5 coordination. In this latter configuration the nearest carbon atom shows signs of sp^3-hybridization and the other four carbons adopt a cis-butadiene-like structure. In the hetero-systems we find distinct geometries with each M-Cp unit adopting the coordination of the homo-dimetallocene.


Until next time, kids - drink your V-8 and take your vitamins!

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