Is cardioplegia system pressure the optimal measure of coronary perfusion during antegrade cardioplegia delivery? A critical review of pressure measurements for optimal antegrade delivery.

Antegrade cardioplegia is routinely given during cardiac surgery. The delivery of antegrade cardioplegia from the cardiopulmonary bypass machine has many variables. Many perfusionists rely exclusively on cardioplegia system pressure to ensure safe antegrade delivery.

Fluoreno[2,1-a]fluorene: an ortho-naphthoquinodimethane-based system with partial diradical character.

Fluoreno[2,1-a]fluorene, a molecule comprising fused ortho-quinodimethane units in a 1,5-napthoquinodimethane core, has been prepared and investigated with spectroscopy (UV-Vis-NIR, H-NMR and Raman), SQUID magnetometry, spectroelectrochemistry and quantum chemistry. While para-quinodimethanes with a 2,6-substitution pattern exist as closed-shell species and meta-quinodimethanes with 2,7-substitution favour a ground electronic state with very large diradical character, our 1,5-substituted ortho-naphthoquinodimethane-based system exhibits an intermediate degree of diradical character.

Oxodealkenylative Cleavage of Alkene C(sp )-C(sp ) Bonds: A Practical Method for Introducing Carbonyls into Chiral Pool Materials.

Reported herein is a one-pot protocol for the oxodealkenylative introduction of carbonyl functionalities into terpenes and terpene-derived compounds. This transformation proceeds by Criegee ozonolysis of an alkene, reductive cleavage of the resulting α-alkoxy hydroperoxide, trapping of the generated alkyl radical with 2,2,6,6-tetramethylpiperidin-1-yl (TEMPO), and subsequent oxidative fragmentation with MMPP. Using readily available starting materials from chiral pool, a variety of carbonyl-containing products have been accessed rapidly in good yields.

Synthesis and Electronic Properties of Fluoreno[2,1-a]fluorenedione and Fluoreno[1,2-a]fluorenedione.

The [2,1-a]- and [1,2-a]-isomers of fluorenofluorenedione have been synthesized via intramolecular Friedel-Crafts acylations. DFT calculations indicate that the [1,2-a]-isomer adopts a twisted, helical C-symmetric structure and that its protonated form is the thermodynamic product of the Friedel-Crafts acylation in hot sulfuric acid. Absorption spectroscopy and cyclic voltammetry measurements provide experimental estimations of frontier molecular orbital energy levels, which are reported and discussed.