FUNCTIONAL DETERGENT PROBES OF MICELLE STRUCTURE. ABSORPTION, FLUORESCENCE AND QUENCHING MEASUREMENTS

Abstract— The absorption and fluorescence spectra of two functional ionic detergents containing an indole chromophore have been studied as micelle probes and have been compared to the corresponding spectra of 1-methylindole. The quenching of the fluorescence of the probes by NO^-₂ and Co²⁺ has also been investigated. Based on the results obtained, it is concluded that 1-methylindole is associated with the surface of HDTBr micelles, whereas it is located in the interior of SDS micelles. The chromophore of the indole detergents is considered to be located in the interior of HDTBr and SDS micelles.     

Natural abundance 13C13C coupling constants observed via double quantum coherence. The two-dimensional ‘inadequate’ experiment for 13C NMR spectral analysis of erythronolide - B

A one- and a two-dimensional INADEQUATE NMR experiment afforded one-bond ¹³C¹³C coupling constants at natural abundance and total unambiguous signal assignment for erythronolide-B (1). ¹³C¹³C coupling constants at natural abundance and total unambiguous signal assignment for erythronolide-B (1).     

Computer-assisted determination of carbon connectivity patterns based on natural abundance one-bond 13C13C coupling constants: terpenes

With the help of the interactive computer program CABSA the carbon connectivity pattern of representative known terpenes was established by measuring the one-bond ¹³C¹³C coupling constants in the presence of the signals of molecules containing one ¹³C isotope.     

Ideal tetrafunctional amphiphilic PEG/PDMS conetworks by a dual‐purpose extender/crosslinker. I. Synthesis

The synthesis of a new type of amphiphilic conetwork (APCN) consisting of well‐defined hydrophilic poly(ethylene glycol) (PEG) and hydrophobic polydimethylsiloxane (PDMS) segments is described. The conetwork is ideal (the lengths of each PEG and PDMS chain segments, respectively, are identical) and tetrafunctional (exactly four chains emanate from each crosslink site). The synthesis of the conetworks was achieved by the use of a novel dual‐purpose extender/crosslinker Y (bis [(dimethylsilyl)oxy]‐[(etoxydimethylsilyl)oxy]phenylsilane, (SiPh(SiH)₂OEt)), in two steps: (1) Synthesis of a new linear random multiblock copolymer (MBC) (AY)_n(BY)_m, where A is the hydrophilic PEG and B is the hydrophobic segment, and (2) Crosslinking the multiblocks by catalytic condensation of the SiOEt groups in the Y units. The extender/crosslinker fulfills two totally different functions: First, it extends two incompatible hydrophilic and hydrophobic prepolymers (PEG and PDMS) to a random MBC, and, subsequently, it cross‐links the multiblocks to the target APCN. The synthesis and characterization of the extender/crosslinker is also presented. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4953–4964, 2005     

Binuclear organometallic compounds VIII. Oxidative addition of Si-H or Si-Cl compounds to low valent Fe, Co, or Ni complexes stabilised by mono- or bi-dentate phosphines

The reactions of [(Ph₃P)₄Ni], [(Ph₃P)₃CoN₂], [(dp)₂Ni], [(dp)₂CoH], [(dp)₂Fe(C₂H₄)] or [(dp)₂FeH₂] (dp = Ph₂PCH₂CH₂Ph₂P) with Ph_nSiCl_4-n (n = 1, 2, or 3), Ph_nSiH_4-n, X₃SiH (X = Cl or Et), or R₂ClSiH (R = Ph or Me) have been investigated. Solid complexes were isolated which, for the most part, were insoluble in non-polar solvents. Assignments of structures are therefore incomplete, and are based on microanalysis, IR spectra, analogies with established reactions, and (in some cases) chemical degradation. Evidence is presented for the following: (i) for Ni^II, products from [(Ph₃P)₄Ni] and HSiXX′X″ (XX′X″ = Ph₃, Ph₂H or PhH₂), the cyclic [(Ph₃P)₂NiSiCl₂]₂, and the five-coordinate [(dp)₂-NiX]⁺[SiCl₃]^- (X = H or Cl₃Si); (ii) for Co^III, the six-coordinate cis-octahedral [(dp)₂CoH₂]⁺ [SiXX′X″]^- (XX′X″ = Cl₃, Cl₂Me, ClMe₂, or ClPh₂); and for Fe^II, the four-coordinate [(dp)FeH(SiCl₃)] and the six-coordinate [(dp)₂Fe(X)SiCl₃] (X = H, Cl, or Cl₃Si).     

A problem in prediction theory

Summary A new kind of ? prediction problem ? is defined and studied, first for certain special distributions and then generally. The general results are connected with conjugate trigonometric series. To Giovanni Sansone on his 70^th birth day. The authors acknowledge the support of theAlfred P. Sloan Foundation and the National Science Foundation, respectively.