The crystal structure of 1,1′-bisisoquinoline, C₁₈H₁₂N₂

Abstract

C 18 H 12 N 2 , tetragonal, I41/a (no. 88), a = 13.8885(6) Å, c = 13.6718(6) Å, V = 2637.2(3) Å 3 , Z = 8, Rgt(F) = 0.0295,

1,1′-Biisoquinolines—Neglected Ligands in the Heterocyclic Diimine Family That Provoke Stereochemical Reflections

“…Only a single example of a 1,1 -biisoquinoline N,N'-dioxide has been structurally characterized in a co-crystal of (1P)-1,1 -biisoquinoline N,N'-dioxide and (1M)-[1,1 -binaphthalene]-2,2 -diol [98]. A comparison of the N2-C1-C1 -N2 torsion angle in 1,1 -biisoquinoline (90.96 • ) [108] to that in 1,1 -biisoquinoline N,N'-dioxide (101.64 • ) [98] (101.64 • ) shows that the oxygen-oxygen interactions dominate and these substituents adopt an anti comformation (Figure 6b). [98] showing the importance of oxygen-oxygen interactions.…”

“…The complex [Re{(1MP)-biiq)(CO) 3 Cl]•PhMe has been structurally characterized (Figure 10) and has the expected octahedral structure with two carbonyl ligands trans to the biiq N-donor atoms (CSD Refcode AYUPER, space group P1) [125]…”

The crystal structure of 1,12-diazaperylene, C18H10N2

“…The title compound was synthesized by a reductive cyclization reaction of 1,1′-bisisoqulinoline [4,5] in dimethoxyethane using potassium as reducing agent [6]. After synthesis, the residue was chromatographed on aluminium oxide with THF and concentrated under reduced pressure.…”

Synthesis and Coordination Chemistry of a Benzannulated Bipyridine: 6,6′-Biphenanthridine

“…The ability of the two N-heterocycles to rotate about the adjoining single bond is also evident, with a 72.6°angle between the planes of the two phenanthridine units (torsional angle N1−C1−C1′−N1′ = 71.6°). In comparison, the two quinoline subunits of 1,1′-biisoquinoline are oriented nearly perpendicular [88.54(1)°] to one another, 46 while the two pyridine moieties in 2,2′-bipyridine are coplanar in the solid state. 47 Within this series, the C−C bond connecting the two N-heterocycles extends slightly with benzannulation: 2,2′bipyridine 1.4881(13) Å, 47 1,1′-biisoquinoline 1.496(2) Å, 46 and 6,6′-biphenanthridine 1.5004(18) Å.…”

“…In comparison, the two quinoline subunits of 1,1′-biisoquinoline are oriented nearly perpendicular [88.54(1)°] to one another, 46 while the two pyridine moieties in 2,2′-bipyridine are coplanar in the solid state. 47 Within this series, the C−C bond connecting the two N-heterocycles extends slightly with benzannulation: 2,2′bipyridine 1.4881(13) Å, 47 1,1′-biisoquinoline 1.496(2) Å, 46 and 6,6′-biphenanthridine 1.5004(18) Å. The space-filling diagram (Figure 2b) highlights the steric clash of the hydrogen nuclei in the 7/7′ positions (C3 and C3′) that is typical of 1,1′-biisoquinoline-type motifs.…”