1,8-Bis(diphenylphosphino)biphenylene. A new ligand for late transition metal complexes

Abstract

The synthesis of the isomeric compounds 1,8-bis(diphenylphosphino)biphenylene (1) and 1,5-bis(diphenylphosphino)biphenylene (2) is reported. Compound 1 was used as bidentate ligand towards late transition metal chlorides giving rise to six complexes 1·MCl2 (M=Ni, Pd, Pt) and 1·MCl (M=Cu, Ag, Au), which have been fully characterized. The electronic bond characteristics of the polar-covalent M–P and M–Cl bonds of 1·MCl2 (M=Ni, Pd, Pt) and 1·MCl (M=Cu, Ag, Au) were determined by a computational real-space bonding indicator (RSBI) analyses including the atoms-in-molecules, electron localizability indicator, and non-covalent interactions (NCI) index methods based on the molecular structures established by single crystal X-ray diffraction. Consistent with the electronegativity differences, the polarity of the M–Cl bonds is found to be systematically higher compared to the M–P bonds. In addition, there is a tendency for decreasing bond polarities downwards the column (Ag–P is an exception). Consequently, the highest bond polarities are observed for the Ni–Cl and Cu–Cl bonds, whereas the lowest polarities are observed for the Pt–P and Au–P bonds.

Structural Variety of Iron Carbonyl Clusters Featuring Ferrocenylphosphines

“…In addition to 12 a and 12 b , also 12 c featuring two PH units was formed and observed as the e , e ‐isomer exclusively. In contrast to 12 a , where the a , a ‐isomer is dominant (X=Cl), the e , e ‐product in 12 c is most probably preferred, due to its lower steric demand in the axial position [27] . The assignment as e , e is in accordance with its 31 P{ 1 H} NMR resonance signal, which appears as the most low‐field shifted signal for PH fragments at 83.4 ppm compared to those where an a ‐configuration was assigned 12 b ( a , a : 72.3; e , a : 75.7 ppm).…”

“…Furthermore, the 1,8‐C⋅⋅⋅C distance in rigid 1,8‐naphthalenyl fragments, which should ideally be equal to the P⋅⋅⋅P separation in the respective bisphosphine ligand, is increased from ∼2.50 Å [43] to 2.74 Å [42] . Other rigid bisphosphinyl motifs, such as biphenylene (C⋅⋅⋅C ∼3.65 Å), [27] xanthene (C⋅⋅⋅C ∼4.3–4.8 Å) [44] , and [2.2]paracyclophane (C⋅⋅⋅C 3.1–3.5 Å) [45] have so far not been used in metal carbonyl cluster chemistry, wherefore comparison is limited to the mentioned examples above. Herein, the P⋅⋅⋅P distance reaches its maximum for a , a ‐ 12 a (2.8848(15) Å), most probably due to an electronic repulsion of the π‐systems of both ferrocenyls.…”

“… Unique geometrical properties of the ferrocenyl‐ compared to phenyl‐based motifs represented by their ypso (top) and P⋅⋅⋅P distance (bottom) in their non‐bended/distorted shapes. (Values were calculated [26] based on reference [27] and herein reported compounds).…”

Recent Advances of Biphenylene: Synthesis, Reactions and Uses

“…In 2018, Mebs, Beckmann, and co‐workers synthesized a new diphosphane ligand 95 from 64 (Scheme ) . This ligand could readily coordinate to various transition metals to give a mono‐ or bi‐metallic complex.…”

In silico capture of noble gas atoms with a light atom molecule

“…The conceptual design employs perisubstituted ligand systems consisting of organic spacerfragments, which are typically used to enforce atom-atom contacts. [64][65][66][67][68][69][70][71][72] Linking three of such spacer fragments, e.g. acenaphthalene, biphenylene, (thio)xanthene moieties together by a central HSi group (tripodal ligand design) provides a dynamically confined space, the size of which depends on the spacer type and the substituent in the peri-position (''starting state'').…”