Synthetic and Structural Study of peri-Substituted Phosphine-Arsines

Abstract

A series of phosphorus-arsenic peri-substituted acenaphthene species have been isolated and fully characterised, including single crystal X-ray diffraction. Reactions of EBr3 (E = P, As) with iPr2PAcenapLi (Acenap = acenaphthene-5,6-diyl) afforded the thermally stable peri-substitution supported donor–acceptor complexes, iPr2PAcenapEBr23 and 4. Both complexes show a strong P→E dative interaction, as observed by X-ray crystallography and 31P NMR spectroscopy. DFT calculations indicated the unusual As∙∙∙As contact (3.50 Å) observed in the solid state structure of 4 results from dispersion forces rather than metallic interactions. Incorporation of the excess AsBr3 in the crystal structure of 3 promotes the formation of the ion separated species [iPr2PAcenapAsBr]+Br− 5. A decomposition product 6 containing the rare [As6Br8]2– heterocubane dianion was isolated and characterised crystallographically. The reaction between iPr2PAcenapLi and EtAsI2 afforded tertiary arsine (BrAcenap)2AsEt 7, which was subsequently lithiated and reacted with PhPCl2 and Ph2PCl to afford cyclic PhP(Acenap)2AsEt 8 and acyclic EtAs(AcenapPPh2)2 9.

Halogen-Bonded Supramolecular Parallelograms: From Self-Complementary Iodoalkyne Halogen-Bonded Dimers to 1:1 and 2:2 Iodoalkyne Halogen-Bonded Cocrystals

“…Nonetheless, a type I interaction with a Cl•••Cl separation of 2.669 Å between dichloromethane molecules (without disorder) was found in the structure of the bis(6-bromo-1,2-dihydroacenaphthylen-5yl)(ethyl)arsane dichloromethane solvate. 40 The separation we report here is close enough to suggest that the major component of the disorder is preferentially paired with the minor component, thereby mostly avoiding close contact. No additional solvent-accessible void spaces were detected using a 1.2 probe radius.…”

“…Of the 125 distinct instances with Cl···Cl separations within the range of 2.6 to 3.4 Å, 12 of the 14 shorter distances, all less than 3.000 Å, involved disordered dichloromethane molecules. Nonetheless, a type I interaction with a Cl···Cl separation of 2.669 Å between dichloromethane molecules (without disorder) was found in the structure of the bis (6-bromo-1,2-dihydroacenaphthylen-5-yl)­(ethyl)­arsane dichloromethane solvate . The separation we report here is close enough to suggest that the major component of the disorder is preferentially paired with the minor component, thereby mostly avoiding close contact.…”

Incipient Nucleophilic Attack on a Carbonyl Group Adjacent to a Stereogenic Centre in Peri Naphthalene Derivatives

“…Examples include a NMe 2 or OMe group with an aldehyde, alkene, alkyne or nitrile, [5–8] hydrogen bonding to an amide nitrogen atom [9,10] or to a π‐surface, [11] novel Si−H⋅⋅⋅B bonds, [12] construction of abnormally long bonds, [13] methods for determining the degree of bonding between peri‐ groups, [14] and the promotion of reactions between groups held close together [15] . Peri‐ naphthalenes also occur in some proton sponges, [16] and systems with frustrated lone pairs, [17] while peri ‐acenaphthenes have been used to investigate interactions between the heavier main group elements [18,19] . Particularly notable investigations have involved substitution reactions at silicon, [20] characterisations of the interaction of a −F group, or reaction of a thiolate group, with an amide carbonyl group, [21,22] a system for the release of S=O from a peri ‐naphthalene [23] and a recent study of a 1,5 hydride shift facilitated by peri ‐interactions [24] …”

“…[15] Peri-naphthalenes also occur in some proton sponges, [16] and systems with frustrated lone pairs, [17] while peri-acenaphthenes have been used to investigate interactions between the heavier main group elements. [18,19] Particularly notable investigations have involved substitution reactions at silicon, [20] characterisations of the interaction of a À F group, or reaction of a thiolate group, with an amide carbonyl group, [21,22] a system for the release of S=O from a peri-naphthalene [23] and a recent study of a 1,5 hydride shift facilitated by peri-interactions. [24] The studies on a series of peri-naphthalene and -acenaphthenes representing an aza-Michael reaction (Me 2 N/C=CZ 2 , Z = electron-withdrawing group), with interactions ranging from initial n-π* interaction to partially completed bond formation has led to the construction of a reaction pathway and to measurement of bonding charge density between reacting groups as the bond forms.…”

Synthesis of a 1-aza-2-phospha-acenaphthene complex profiting from coordination enabled chloromethane elimination

“…11 These compounds showed an increased stability towards redox decomposition pathways due to the geometrically enforced acid–base interaction. 12 The coordination chemistry of group 13–15 element peri -substituted compounds (primarily of acenaphthene derivatives) are of great interest as illustrated in the review by Kilian in 2011, 13 and many new developments have occurred since. 14–21 Intramolecularly amino-stabilized phosphanes are of special interest due to a potentially increased electron density at the phosphorus.…”