Bispidine Platform as a Tool for Studying Amide Configuration Stability

In this work, the solution conformations of seventeen 3,7-diacyl bispidines were studied by means of NMR spectroscopy including VT NMR experiments. The acyl groups included alkyl, alkenyl, aryl, hetaryl, and ferrocene moieties. The presence of syn/anti-isomers and their ratios were estimated, and some reasons explaining experimental facts were formulated. In particular, all aliphatic and heterocyclic units in the acylic R(CO) fragments led to an increased content of the syn-form in DMSO-d6 solutions. In contrast, only the anti-form was detected in DMSO-d6 and CDCl3 in the case when R = Ph, ferrocenyl, (R)-myrtenyl. In the case of a chiral compound derived from the natural terpene myrtene, a new dynamic process was found in addition to the expected inversion around the amide N-C(O) bond. Here, rotation around the CO-C=C bond in the acylic R fragment was detected, and its energy was estimated. For this compound, ΔG for amide N-C(O) inversion was found to be equal to 15.0 ± 0.2 kcal/mol, and for the rotation around the N(CO)–C2′ bond, it was equal to 15.6 ± 0.3 kcal/mol. NMR analysis of the chiral bispidine-based bis-amide was conducted for the first time. Two X-ray structures are reported. For the first time, the unique syn-form was found in the crystal of an acyclic bispidine-based bis-amide. Quantum chemical calculations revealed the unexpected mechanism for amide bond inversion. It was found that the reaction does not proceed as direct N-C(O) bond inversion in the double-chair (CC) conformation but rather requires the conformational transformation into the chair–boat (CB) form first. The amide bond inversion in the latter requires less energy than in the CC form.

Squares of Colour

This chapter explores the cultural position of two women artists, Saloua Raouda Choucair (1916–2017) and Etel Adnan (b.1925) in the second half of the 20th century in Lebanon. The strong presence of abstraction in their work calls for a reflection on materiality and abstraction, and on form and anti–form. Choucair and Adnan pioneered new ways of seeing, of thinking about art and its physical relationship to it through abstract aesthetics. Born in Lebanon, they have become significant artists who trained and lived abroad, while always keeping strong links to Lebanon. Their oeuvres present a reflection on the conflicted Western and Islamic heritage in Lebanon and in the Middle East at large. Although abstraction is no clear representation of female subjectivity, the use of abstraction as lived experience in Choucair’s and Adnan’s works serve to explore gender in Lebanon as a subjective and social context.

Folds in the Fabric: Robert Morris in the 1980s

At the beginning of the 1980s, Robert Morris took a decisive and shocking turn. Abandoning the strategies of agency reduction, abstraction, and indeterminacy that had guided his practice since the 1960s, he began to make paintings instead. Architectural in scale and gaudy in their depictions of eviscerated human remains and post-apocalyptic landscapes, the new paintings trafficked in those myths of painting that Neo-Expressionism was just then resurrecting as bankable signs for a consumerist decade: expressivity, figuration, and narrative, among them. What, then, could unite the theorist of anti form—maker of the process-based, anti-object folds, tangles, and mounds of felt and thread waste—with the painter of the baroque, Neo-Expressionist daubs? This paper argues that the paintings of the 1980s, despite their seeming reversals, provide a key for understanding Morris's way of working from his earliest lead and felt projects forward. What they reveal, in short, is an oeuvre guided by a baroque logic of “the fold,” an aesthetic of non-invention that aimed, not at creating but at commandeering and multiplying, for better or worse, existing aesthetic and discursive structures, be they those of Conceptual art, post-Minimalism, or Neo-Expressionism.

Crystal structures of the bis-bidentate N2S2 Schiff base ligand and its copper(I) coordination polymer

A new flexible bis-bidentate N2S2 Schiff base ligand (2,4-Cl-ba)2dapte = N,Nʹ-bis-(2,4-dichlorobenzaldehyde)-1,2-di(o-iminophenylthio)ethane and its copper(I) coordination polymer [Cu2(μ-I)2(μ-(2,4-Cl-ba)2dapte)]n, were synthesized and characterized by CHN elemental analysis, FT-IR and UV-Vis spectroscopy and single-crystal X-ray diffraction. The molecule of (2,4-Cl-ba)2dapte adopts a trans conformation of the 1,2-di(o-iminophenylthio)ethane unit. The (2,4-Cl-ba)2dapte acts as a bis-bidentate ligand with two iminic nitrogen and two sulfur atoms, coordinating to copper(I) ions in an anti-form leading to the dinuclear Cu2(μ-(2,4-Cl-ba)2dapte) groups. These groups are then bridged by two iodide anions to form a copper(I) coordination polymer [Cu2(μ-I)2(μ-(2,4-Cl-ba)2dapte)]n. The coordination geometry around the copper(I) ions is a distorted tetrahedron. Finally, a nano-sized form of the copper(I) coordination polymer [Cu2(μ-I)2(μ-(2,4-Cl-ba)2dapte)]n was prepared by an ultrasonic bath assisted process and characterized by elemental analysis, FT-IR and SEM.

A NATION BECOMING? MEDIATING POST-APARTHEID IDENTITIES IN ANTJIE KROG’S COUNTRY OF MY SKULL

 In this paper I use postmodernism to explore Antjie Krog’s engagement with post-Apartheid identities in Country of My Skull. These identities, often complex and multiple, are mediated in the process of nation-building. I take the exercise of the Truth and Reconciliation Commission (TRC) as metonymy for the nation-building project, and I argue that Krog quite deliberately chose an ambiguous and complex genre to represent equally ambiguous and complex identities. One of the salient features of postmodernism is its anti-systemic, anti-form impulse, and the form that Krog uses refuses to be conscripted into any single conventional form. Dominated by testimonies of victims and perpetrators of apartheid violence, the form also bears aspects of autobiography, novel, poetry and journalistic snippets interlaced with quotes from psychoanalysts and philosophers. From time to time, anecdotes, fairytales, myths and legends are interpolated into the narrative to remind the reader of the porous borders between fiction and reality.