ABSTRACT
Aluminum aminoterephthalate MOF particulate materials (NH(2)-MIL-101(Al) and NH(2)-MIL-53(Al)), studied here as components of self-detoxifying surfaces, retained their reactivity following their covalent attachment to protective surfaces utilizing a newly developed strategy in which the MOF particles were deposited on a reactive adhesive composed of polyisobutylene/toluene diisocyanate (PIB/TDI) blends. Following MOF attachment and curing, the MOF primary amino groups were functionalized with highly nucleophilic 4-methylaminopyridine (4-MAP) by disuccinimidyl suberate-activated conjugation. The resulting MOF-4-MAP modified PIB/TDI elastomeric films were mechanically flexible and capable of degrading diisopropyl fluorophosphate (DFP), a chemical threat simulant.
ABSTRACT
Treatment of a bis(phenylphosphonite)calix[5]arene ligand with either palladium(II) chloride or 1,5-cyclooctadieneplatinum(II) chloride yields square planar metal complexes in which the two phosphorus atoms bind cis to the MCl(2) moiety (M = Pd, Pt). Chloride was removed from the palladium complex to open a coordination site at the metal for catalysis. The chloride removal resulted in a rare and unexpected η(6) coordination of an arene to the metal. The reaction is reversible upon addition of tetra-n-butyl ammonium chloride.
ABSTRACT
Silica thin films and nanoparticles prepared using sol-gel chemistry are derivatized with active molecules to generate new functional materials. The mild conditions associated with sol-gel processing allow for the incorporation of a range of dopants including organic or inorganic dyes, biomolecules, surfactants, and molecular machines. Silica nanoparticles embedded with inorganic nanocrystals, and films containing living cells have also been synthesized. Silica templated with surfactants to create mesostructure contains physically and chemically different regions that can be selectively derivatized using defined techniques to create dynamic materials. Using two different techniques, donor-acceptor pairs can be doped into separated regions simultaneously and photo-induced electron transfer between the molecules can be measured. Mesoporous silica materials are also useful supports for molecular machines. Machines including snap-tops and nanoimpellers that are designed to control the release of guest molecules trapped within the pores are described. Mesoporous silica nanoparticles are promising materials for drug delivery and other biomedical applications because they are nontoxic and can be taken up by living cells. Through appropriate design and synthesis, multifunctional mesoporous silica nanoparticles for sophisticated bio-applications are created.
ABSTRACT
New calix[5]arene trivalent phosphorus derivatives have been synthesized which should be excellent ligands with which to study and control the interaction of a ligand atom with a metal. The larger cavity of the calix[5]arene (compared to calix[4]arene) provides a good balance between constraint and flexibility. Treatment of p-tert-butylcalix[5]arene with 2 equiv of either tris(dimethylamino)phosphine or dichlorophenylphosphine inserts two RP moieties into the calix[5]arene framework to give calix[5](PR)2(OH) (1, R = Me2N; 2, R = Ph). Further treatment of 1 with 4 equiv of HCl gives calix[5](PCl)2(OH) (3). Heating a solution of the monophosphorus compound calix[5](PNMe2)(OH)3 (4) releases dimethylamine to yield both monomeric calix[5](P)(OH)2 (6) and dimeric [calix[5](P)(OH)2](2) (7), the latter having a tubelike geometry. X-ray crystallographic studies confirm the structures and show that 1 and 2 have approximate cone conformations while 3 has an approximate 1,2-alternate conformation. The orientations of the phosphorus lone pairs and oxygen atoms in all derivatives provide a framework for both soft and hard ligand interactions within the calix[5]arene.
