Reaction of the heteronuclear cluster RuOs3(μ-H)2(CO)13 with azulenes

Abstract

a b s t r a c t h 3 -C 10 H 5 Me 2 i Pr) (6), respectively. In 3e5, cluster-to-ligand hydrogen transfer appears to have taken place, with the organic moiety capping a trimetallic face in 3, bridging a metalemetal bond in 4 and via a m 3 ,h 5 :s 2 bonding mode in 5a and 5b. Cluster 6 contains a trigonal bipyramidal metal framework with the guaiazulene ligand over a triangular metal face. All five clusters have been completely characterised, including by single-crystal X-ray diffraction analysis.

Merging of inner and outer ruthenium organometallic coordination motifs within an azuliporphyrin framework

“…Analogous coordination shifts were previously detected in the 1 H NMR and 13 C NMR spectra of the ruthenium cluster -regular azulene complexes. 13,14 Coupling constants for azulene protons have also decreased from about 10 Hz, typical for azulene derivatives, to a range of 6-8 Hz.…”

“…1). These values: 1 H NMR -3.06 H(2 1 ,3 1 ), 1.54 H(2 2 ,3 2 ), 4.80 H(2 3 ) ppm; 13 C NMR -68.3 C(2 1 ,3 1 ), 70.2 C(2 2 ,3 2 ), 102.5 C(2 3 ) ppm, clearly point toward the azulene moiety acting as a coordinating unit. Analogous coordination shifts were previously detected in the 1 H NMR and 13 C NMR spectra of the ruthenium cluster -regular azulene complexes.…”

“…1), resemble the basic pattern of the azuliporphyrin consistent with its borderline aromaticity. 8,9 The typical spectrum of 2 affords an The remarkable relocations of 1 H and 13 C azulene resonances of 3 ) ppm) reflect a cluster attachment. Actually, the change in the azuliporphyrin coordination mode determined for 3 can be readily appreciated by an analysis of coordination shifts defined here as 1 H or 13 C chemical shift differences between 2 and 3 at chosen positions (Fig.…”

“…8,9 The typical spectrum of 2 affords an AB spin system at d = 7.70, H(7,18), and d 7.62 ppm, H (8,17), with a coupling constant ( 3 J = 4.9 Hz) typical for a pyrrole ring in porphyrinoids, which is accompanied by a singlet at d = 7.69 ppm from H(12,13) of the central pyrrole unit. The NMR resonances of an azulene unit have been assigned to 2, namely: 1 H NMR -6.80 H(2 1 ,3 1 ), 6.38 H(2 2 ,3 2 ), 6.64 H(2 3 ) ppm; 13 C NMR -131.5 C(2 1 ,3 1 ), 136.9 C(2 2 ,3 2 ), 135.1 C(2 3 ) ppm.…”

“…The remarkable relocations of 1 H and 13 C azulene resonances of 3 ( 1 H NMR: 3.74 H(2 1 ,3 1 ), 4.84 H(2 2 ,3 2 ), 1.84 H(2 3 ) ppm; 13 C NMR: 63.2 C(2 1 ,3 1 ), 66.7 C(2 2 ,3 2 ), 32.3 C(2 3 ) ppm) reflect a cluster attachment. Actually, the change in the azuliporphyrin coordination mode determined for 3 can be readily appreciated by an analysis of coordination shifts defined here as 1 H or 13 C chemical shift differences between 2 and 3 at chosen positions (Fig. 1).…”