[2‐{E(CH₂CH₂)₂NCH₂}C₆H₄]_nBiX_3–n (E = O, NMe; X = Cl, Br, I; n = 1–3) and [2‐(Me₂NCH₂)C₆H₄]BiBr₂ – New Hypervalent Organobismuth(III) Compounds

Abstract

The homoleptic [2‐{E(CH2CH2)2NCH2}C6H4]3Bi [E = O (1), MeN (2)], the chlorides [2‐{E(CH2CH2)2NCH2}C6H4]2BiCl [E = O (3), MeN (4)] and the dichlorides [2‐{E(CH2CH2)2NCH2}C6H4]BiCl2 [E = O (5), MeN (6)] were synthesized by reaction of the corresponding ortho‐lithium derivative with BiCl3 in corresponding molar ratios. The dihalides [2‐{E(CH2CH2)2NCH2}C6H4]BiX2 [X = Br, E = O (7), MeN (9); X = I, E = O (8), MeN (10)] as well as [2‐(Me2NCH2)C6H4]BiBr2 (11) were obtained by halide exchange reactions between RBiCl2 and excess aqueous solution of KX. The compounds were characterized by multinuclear (1H, 13C) NMR spectroscopy and mass spectrometry. The crystal and molecular structures of 1–5 and 11 were determined by single‐crystal X‐ray diffraction. In all compounds the (C6H4CH2)N nitrogen atoms are coordinated to bismuth. The crystals of 1 and 2, as well as those of the chlorides 3 and 4, contain discrete molecules. For R3Bi intramolecular N→Bi interactions of medium strength [Bi(1)–N(1) 3.170(7) Å for 1 and 3.211(5) Å for 2] result in an overall distorted octahedral (C,N)3Bi core. In the monochlorides one nitrogen atom is strongly coordinated to the bismuth atom [2.660(11) Å for 3 and 2.744(14) Å for 4] trans to the halogen atom, whereas the second one is involved in a weaker intramolecular N→Bi interaction [3.095(11) Å for 3 and 3.061(14) Å for 4] trans to a carbon atom. The overall (C,N)2BiCl core is distorted square‐pyramidal. The crystals of the monohalides 5 and 11 contain discrete dimer units. The pendant arm nitrogen atom is strongly coordinated [2.548(9) Å for 5 and 2.485(13) Å for 11] trans to the bridging halogen atom, thus resulting in an overall distorted square‐pyramidal (C,N)BiX3 (X = Cl, Br) core. The six‐membered morpholinyl and piperazinyl rings in 1–5 adopt the chair conformation, which prevents intramolecular coordination of the oxygen or N(Me) nitrogen atoms to bismuth. Supramolecular architectures based on intermolecular Bi···Br interactions, Cl···H, and Br···H contacts are formed in the crystals of 3, 5, and 11.

From Dibismuthenes to Three‐ and Two‐Coordinated Bismuthinidenes by Fine Ligand Tuning: Evidence for Aromatic BiC3N Rings through a Combined Experimental and Theoretical Study

“…The Cl atoms are placed mutually in trans positions [the corresponding Cl‐Bi‐Cl bonding angles are 175.74(4)° in 4 and 176.52(9)° in 5 ]. This is in contrast to the other structurally related N,C‐chelated bismuth compounds, where primary22b BiCl bonds adopt mutual cis conformation, such as in [C 6 H 4 ‐2‐(CHN‐2′,6′‐ i Pr 2 C 6 H 3 )]BiCl 2 [90.21(7)°]22c or [C 6 H 4 ‐2‐(CH 2 NC 4 H 8 O)]BiCl 2 [90.92(3)°] 22d. This finding should be ascribed to the presence of the bulky t Bu group in the ortho position.…”

Oxidative Addition of Diphenyldichalcogenides PhEEPh (E = S, Se, Te) to Low-Valent CN- and NCN-Chelated Organoantimony and Organobismuth Compounds

“…The central Bi 2 Cl 2 ring is strongly puckered, which may be ascribed to the syn position of both ligands L 1 and both lone pairs of the central atoms on this ring. This type of coordination is quite unusual, because similar dimeric organobismuth systems containing one NC chelating ligand prefer an anti environment of the ligands with an essentially planar central Bi 2 Cl 2 ring …”

Synthesis and Molecular Structure of Pseudo‐Hexacoordinated Pnictines Bearing 2‐Phenylpyridine Ligands

“…The Sb ··· N bond lengths of 1 are shorter than those of other known (pseudo‐)hexacoordinated stibines that possess three Sb ··· N interactions. [ 27,34,35,37,38,40,41 ] Similarly, the Bi ··· N bond lengths of 2 are shorter than those of other known (pseudo‐)hexacoordinated bismuthines such as (Et 2 NCH 2 C 6 H 4 ) 3 Bi [3.214(7) Å]. [ 36 ] These results are interesting because the basicity of the pyridyl group is much lower than that of the amino or imino group.…”

“…[32,33] However, due to the steric hindrance between ligands, there are not many reports of hexaor higher coordinated compounds. Hitherto reported neutral (pseudo-)hexacoordinated stibines (R 3 Sb) and bismuthines (R 3 Bi) contain either amino (A), [34][35][36][37][38] formyl (B), [39] imino (C), [40] or phosphino (D) [27,41] groups as the intramolecular donor (Figure 1a). Although these (pseudo-)hexacoordinated pnictines can be classified as rare 14-Pn-6-type chemical species, detailed investigations into the bonding character and reactivity of these hypervalent species remain scarce.…”