Geminally Substituted Tris(acenaphthyl) and Bis(acenaphthyl) Arsines, Stibines, and Bismuthine: A Structural and Nuclear Magnetic Resonance Investigation

Abstract

Tris(acenaphthyl) and bis(acenaphthyl) substituted pnictogens (iPr2P-Ace)3E (2-4) (E = As, Sb, Bi; Ace = acenaphthene-5,6-diyl) and (iPr2P-Ace)2EPh (5 and 6), (E = As, Sb) were synthesised and fully characterised by multinuclear NMR, HRMS, elemental analysis and single crystal X-ray diffraction.The molecules adopt propeller-like geometries with the restricted rotational freedom of the sterically encumbered iPr2P-Ace groups resulting in distinct NMR features. In the tris(acenaphthyl) species (2-4) the phosphorus atoms are isochronous in the 31 P{ 1 H} NMR spectra, and the rotation of the three acenaphthyl moieties around E-Cipso bond is locked. On the other hand, the bis(acenaphthyl) species show a fluxional behaviour, resulting in an AX to A2 spin system transition in the 31 P{ 1 H} VT NMR spectra. This allowed elucidation of remarkable through-space couplings of 8TS JPP 11.5 Hz (for 5) and 25.8 Hz (for 6) at low temperature. In addition, detailed lineshape analysis of the thermodynamic parameters of the restricted rotation of the "propeller blades" in 5 was performed in the intermediate temperature region and also at coalescence. The lone pairs on the pnictogen atoms in 2-6 are oriented such that they form a bowl shaped area which is somehow buried within the molecule.2

Size Matters: Synthesis of Group 13 Metal‐Substituted Dipnictanes by E‐C Bond Homolysis

“…Deuterated benzene was dried with activated molecular sieves (4 Å) and degassed prior to use. Starting materials LAl, [ 13 ] LGa, [ 14 ] LIn, [ 15 ] PhAsCl 2 , [ 41 ] PhSbCl 2 , [ 42 ] and KCp* [ 43 ] were prepared according to literature procedures. NMR spectra ( δ in ppm) were recorded using a Bruker Avance DPX 300 ( 1 H 300.1 MHz, 13 C{ 1 H} 75.5 MHz) or a Bruker Avance Neo 400 ( 1 H 400.1 MHz, 13 C{ 1 H} 100.6 MHz) spectrometer and were referenced to internal C 6 D 5 H ( 1 H δ = 7.16, 13 C δ = 128.06) or C 6 D 5 CD 2 H ( 1 H δ = 2.08, 13 C δ = 20.43).…”

Tweaking the Charge Transfer: Bonding Analysis of Bismuth(III) Complexes with a Flexidentate Phosphane Ligand

“… 50 The Bi···P distance can be stretched further as in the geminally substituted tris(acenaphthyl) bismuthine E (3.218(3)–3.279(4) Å), in which only weak interactions between the P and Bi centers were found. 51 Recently we have reported a series of phosphane–trihalobismuth complexes ( PS 3 BiX 3 , X = Cl, Br, I), featuring even longer P···Bi distances (in the range of 3.365(1)–3.792(9) Å). The interactions between the P and Bi centers in these PS 3 BiX 3 compounds exhibit a remarkable strength of 7.1–8.8 kcal mol –1 .…”

Sterically Encumbered 4,5‐Bis(diphenylphosphino)acenaphthene Ligand and Its Ni(II), Pd(II), Pt(II), and Cu(I) Complexes

“…[ 18 ] The chemistry of the acenaphthene di‐substituted in peri ‐position with large atoms and groups has been disclosed by Petr Kilian and co‐workers who prepared and studied several acenaphthene derivatives symmetrically and unsymmetrically substituted with phosphorus, tin, thallium, antimony, bismuth, etc. [ 19–23 ] Furthermore, a systematic study on acenaphthene derivatives peri ‐substituted with a diphenylphosphino group and elements of groups 13 and 15 has been reported by Chęcińska, Beckmann, and co‐workers. [ 24 ] Recently, the group of Kilian has reported a detailed study of the coordination chemistry of the unsymmetrical ligand i Pr 2 P‐Ace‐PPh 2 (Figure 1) with several transition metal ions showing that the ligand forms square‐planar complexes with group 10 d 8 metal ions {[( i Pr 2 P‐Ace‐PPh 2 )MX 2 ], M = Ni, Pd, Pt; X = Cl, Br}.…”