A careful choice of the pyrrole building blocks allows the synthesis of a wide range of monohalogenated BODIPY dyes with excellent reactivity in palladium catalyzed coupling reactions.

Mono- and multilayered clay mineral−protein films were constructed with the layer-by-layer deposition technique. The clay mineral saponite and three proteins (protamine, lysozyme, and papain) were tested. Multilayers with up to 15−15 alternating layers of saponite and protein were built up on glass, quartz, and ZnSe. In some cases these supports were primed with the poly(diallyldimethylammonium) cation before clay/protein deposition. The deposition process can be followed by UV and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and by atomic force microscopy (AFM). X-ray diffraction (XRD) patterns confirm the regular ordering of the layers. The “average” protein layer has the thickness of single molecules. The thickness of the “average” saponite layer is proportional to the positive charge density of the protein and varies between 0.6 and 3 elementary saponite sheets. The layers of protamine and lysozyme are stable. However, a small amount of papain is lost upon deposition of the subsequent saponite layer. H−D exchange of proteins in the films is fast and reversible.

The synthesis and energy-transfer properties of a series of oligo(p-phenylene ethynylene)-BODIPY (OPEB) cassettes are reported. A series of oligo(p-phenylene ethynylene)s (OPEs) with different conjugated chain lengths as energy donor subunit in the energy-transfer system were capped at both ends with BODIPY chromophores as energy-acceptor subunits. The effect of the conjugated chain of OPEs on energy transfer in the OPEB cassettes was investigated by UV/Vis and fluorescence spectroscopy and modeling. With increasing number n of phenyl acetylene units (n=1-7), the absorption and emission maxima of OPEn are bathochromically shifted. In the OPEBn analogues, the absorption maximum assigned to the BODIPY moieties is independent of the length of the OPE spacer. However, the relative absorption intensity of the BODIPY band decreases when the number of phenyl acetylene units is increased. The emission spectra of OPEBn are dominated by a band peaking at 613 nm, corresponding to emission of the BODIPY moieties, regardless of whether excitation is at 420 or 550 nm. Furthermore, a very small band is observed with a maximum between 450 and 500 nm, and its intensity relative to that of the BODIPY emission increases with increasing n, that is, the excited state of OPE subunits is efficiently quenched in OPEBn by energy transfer to the BODIPY moieties. Energy transfer (ET) from OPEn to BODIPY in OPEBn is very efficient (all Φ(ET) values are greater than 98 %) and only slightly decreases with increasing length of the OPE units. These results are supported by theoretical studies that show very high energy transfer efficiency (Φ(ET) >75 %) from the OPE spacer to the BODIPY end-groups for chains with up to 15-20 units.