Peter N. Taylor

Enhanced Electronic Conjugation in Anthracene‐Linked Porphyrins

Despite their larger separation, the porphyrin groups in 1 are more strongly conjugated than in analogous compounds in which butadiyne is the bridging unit. This stronger electronic coupling in 1 results in a bathochromic shift in its absorption and emission spectra.

Dramatic enhancement of intrinsic two-photon absorption in a conjugated porphyrin dimer

We report strong cooperative enhancement of simultaneous two-photon absorption cross section in a porphyrin dimer. The two-photon cross section, σ2=6×10−47 cm4s/photon, corresponds to a 400-fold increase over the value measured for the monomer, and is one of the largest ever obtained for organic chromophore of similar size.

CONJUGATED PORPHYRIN OLIGOMERS FROM MONOMER TO HEXAMER

A series of conjugated porphyrin oligomers have been prepared and the evolution in their electronic properties is discussed; the crystal structure of the dimer is presented, as well as the MALDI TOF mass spectrum of the hexamer.

Verstärkte elektronische Konjugation in Porphyrin-Anthracen-Porphyrin-Ketten

Trotz groserer Entfernung sind die Porphyringruppen in 1 starker konjugiert als in der analogen Verbindung, in der sie nur durch eine Butadiin-Einheit verbruckt sind, was sich in einer bathochromen Verschiebung von Absorptions- und Emissionsbanden zeigt.

A stereoselective route to medium-ring cis-1,n-dialkyl-1,n-diphosphacycloalkanes

Quaternisation of 1, (k+ 2)-diphosphabicyclo[k.1.0]alkanes 2, followed by treatment of the monoquaternary salts with alkyllithium or Grignard reagents produces the cis-isomers of 1,n-disubstituted-1,n-diphosphacycloalkanes 3 exclusively; examples containing eight-, nine- and ten-membered rings are described and the structures of two of these compounds 3a and 3f have been determined.

Contents Vol. 5, 2016

Maria Alevizaki – Athens University, Athens, Greece Ana Aranda – Universidad Autónoma de Madrid, Madrid, Spain Rebecca Bahn – Mayo Medical School, Rochester, Minn., USA Paul Banga – King’s College London School of Medicine, London, UK Luigi Bartalena – University of Insubria, Varese, Italy Bernadette Biondi – University of Naples Federico II, Naples, Italy Anita Boelen – Academic Medical Center, Amsterdam, Netherlands Georg Brabant – University of Lübeck, Lübeck, Germany Henning Dralle – Martin Luther University, Halle/Saale, Germany Creswell J. Eastman – The University of Sydney, Westmead, N.S.W., Australia Murat Erdogan – Ibni-i-Sina Hastanesi, Ankara, Turkey Valentin Fadeyev – Federal Endocrinological Scientific Centre, Moscow, Russia Ulla Feldt-Rasmussen – Copenhagen Univ. Hosp., Rigshospitalet, Copenhagen, Denmark Laszlo Hegedus – Odense University Hospital, Odense, Denmark George J. Kahaly – Gutenberg University Medical Center, Mainz, Germany Rui Maciel – Universidade Federal de São Paulo, São Paulo, Brazil Ana Luiza Maia – Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil Jens Mittag – University of Lübeck, Lübeck, Germany Ralf Paschke – Universität Leipzig, Leipzig, Germany Robin P. Peeters – Erasmus MC, Rotterdam, Netherlands

Bicyclic medium-ring diphosphines: contrasting behaviour in the bicyclo[3.3.3]undecane and bicyclo[4.4.4]tetradecane series

Reaction of cis-1,5-dibenzyl-1,5-diphosphacyclooctane 9 with CH2(CH2OTf)2 gives 1,5-dibenzyl-1,5-diphosphoniabicyclo[3.3.3] undecanediium bistriflate 10 which is debenzylated with LiAlH4 to 1,5-diphosphabicyclo[3.3.3]undecane 11, but attempts to prepare 1,6-diphosphabicyclo[4.4.4]tetradecane 7 lead to oligomerisation and rearrangement reactions; 1,5-diphosphoniatricyclo[3.3.3.0]undecanediium bistriflate 8 is slowly formed by reaction of 1,5-diphosphabicyclo[3.3.0] octane with CH2(CH2OTf)2 in nitromethane, but is hydrolysed much more rapidly than its [4.4.4.0] counterpart.