π-dimerization of pleiadiene radical cations at low temperatures revealed by UV–vis spectroelectrochemistry and quantum theory

One-electron oxidation of the non-alternant polycyclic aromatic hydrocarbon pleiadiene and related cyclohepta[ c,d]pyrene and cyclohepta[c,d]fluoranthene in THF produces corresponding radical cations detectable in the temperature range of 293–263 K only on the subsecond time scale of cyclic voltammetry. Although the EPR-active red-coloured pleiadiene radical cation is stable according to the literature in concentrated sulfuric acid, spectroelectrochemical measurements reported in this study provide convincing evidence for its facile conversion into the green-coloured, formally closed shell and, hence, EPRsilent π-bound dimer dication stable in THF at 253 K. The unexpected formation of the thermally unstable dimeric product featuring a characteristic intense low-energy absorption band at 673 nm (1.84 eV; logεmax=4.0) is substantiated by ab initio calculations on the parent pleiadiene molecule and the PF6 − salts of the corresponding radical cation and dimer dication. The latter is stabilized with respect to the radical cation by 14.40 kcal mol−1 (DFT B3LYP) [37.64 kcal mol−1 (CASPT2/DFT B3LYP)]. An excellent match has been obtained between the experimental and TDDFT- calculated UV–vis spectra of the PF6 − salt of the pleiadiene dimer dication, considering solvent (THF) effects.

Cultural policy, literature and readership in revolutionary Cuba: the view from the 21st century

This article presents a fresh perspective on cultural policy in revolutionary Cuba, focusing specifically on the centrality of dialogue with the general readership to the production, reception and regulation of literature. It first summarises the positions regarding revolutionary literature that have been asserted and essayed at various points along the sometimes chaotic trajectory of revolution in Cuba. It then examines reading-related policies and recent attempts within Cuba to re-orient reading practices in the aftermath of the Período Especial [Special Period], and ends by presenting current Cuban debates on the need to mitigate dialogic breakdown between literary text and readership.

All friends now? Critical conversations, West Indian literature and 'The Quarrel with History'

In this essay Alison Donnell returns to the material object of Edward Baugh's essay, published in the pages of the Trinidadian little magazine Tapia in 1977, in order to re-read the force of its arguments in the context of its own politicocultural history and to assess the significance of its publication venue. Donnell attends to Baugh's own standing in the highly charged field of Caribbean literary criticism as a critic of both Walcott and Naipaul, and acknowledges his creative contribution to this field as a poet. She also considers how, in the years between the original publication of Baugh's article and its republication, the questions of historical invisibility have entered newly disputed territories that demand attention to how gender, indigeneity, spirituality, and sexuality shape ideas of historical and literary legitimacy, in addition to those foundational questions around a politics of race and class.

Orde Wingate and the Theory behind the Chindit Operations: Some Recent Findings

This short paper discusses some of the theory behind the Chindit operations in Burma of 1943-44, drawing parallels between Wingate's theoretical concepts post 1990s concepts of 'manoeuvre warfare.'