Coordination of bis(tricarbonylchromium) complexes to small polycyclic aromatic hydrocarbons: Structure, relative stabilities, and bonding

Hexahapto‐Metal Complexes of Single‐Walled Carbon Nanotubes

“…In our previous study, we reported results for titanium, chromium, iron, and gold,54 for which it is known that the metal atoms migrate readily between benzenoid hexahapto complexation sites at room temperature and the van der Waals gap of 3.15 Å within SWNT bundles84 is a good fit for a naked first row transition metal; for example, the separation between benzene rings in (η 6 ‐benzene) 2 Cr is known to be 3.226 Å 85, 86. The first row transition metals are known to be mobile on conjugated carbon surfaces and offer a range of organometallic chemistries 51, 56–58, 81, 87–94.…”

Solid‐state Bis‐hexahapto‐metal complexation of single‐walled carbon nanotubes

“…), with the goal of allowing the metal atoms to diffuse along the SWNT surfaces until they encounter a SWNT–SWNT junction or intra‐bundle contact with a geometry that allows formation of a bis‐hexahapto bond of structure (η 6 ‐SWNT)M(η 6 ‐SWNT) (Scheme b). In the case of chromium for example, the migration of the metal atoms between benzenoid hexahapto complexation sites occurs readily at room temperature and the van der Waals gap of 0.315 nm within SWNT bundles is a good fit for a naked chromium atom based on the separation of 0.3224 nm between benzene rings in (η 6 ‐benzene) 2 Cr …”

“…In the case of chromium for example, the migration of the metal atoms between benzenoid hexahapto complexation sites occurs readily at room temperature and the van der Waals gap of 0.315 nm within SWNT bundles [7] is a good fit for a naked chromium atom based on the separation of 0.3224 nm between benzene rings in (Z 6 -benzene) 2 Cr. [8,9] We report results on the conductivity of purified SWNT films, which have been exposed to the controlled e-beam evaporation of titanium, chromium, iron, and gold atoms, which are known to be mobile on conjugated carbon surfaces and offer a range of organometallic chemistries. [8,[10][11][12][13][14][15][16][17][18][19][20][21] Thus, our approach has some commonality with the well-known metal vapor synthesis technique that has been used to prepare many bis-arene-metal complexes [(Z 6 -arene) 2 M], [15] but adapted to investigate the effect of complexation on the solid-state transport properties of SWNT networks.…”

Forty years of Clar's aromatic π-sextet rule

“…Moreover, it has been proven useful to predict the coordination site of the bis(tricarbonylchromium) complex and the lithium cation to small PAHs (Güell et al,2005; Jiménez-Halla et al, 2008). …”

“…Clar's rule, originally developed for benzenoid compounds, has been successfully used to describe aromaticity in more complex structures as those found in carbon nanotubes, graphene nanoribbons, carbon nanocones, and carbon nanotori (Martín-Martínez et al, 2008 , 2012 , 2013 ; Balaban and Klein, 2009 ; Wassmann et al, 2010 ). Moreover, it has been proven useful to predict the coordination site of the bis(tricarbonylchromium) complex and the lithium cation to small PAHs (Güell et al, 2005 ; Jiménez-Halla et al, 2008 ).…”