The First P‐Stereogenic 1D Coordination Polymers with the Metal Centers in the Backbone

Abstract

The enantiomeric ligands (R,R)-and (S,S)-bis(o-anisylphenylphosphanyl)methane (R, R-22 and S,S-22) and (R,R)-and (S,S)-bis(phenyl-m-xylylphosphanyl)methane (R,R-23 and S,S-23; dppm*), were treated with [Cu(NCCH 3 ) 4 ](BF 4 ) and AgBF 4 to produce the binuclear complexes [Cu 2 (dppm*) 2 -(NCCH 3 ) 4 ](BF 4 ) 2 or [Ag 2 (dppm*) 2 ](BF 4 ) 2 , respectively. Then, these complexes were used as building blocks to prepare the first P-chirogenic 1D coordination polymers {[M 2 (dppm*) 2 -where M is part of the polymer backbone. In the absence of X-ray structure determination, 1 H NMR, chemical analysis, UV/Vis spectrometry, emission spectroscopy, and photophysical measurements were used to unambiguously demonstrate the isostructural nature of these new polymers with the parent dppm-containing polymers 20 and 21. [14] Results and DiscussionSyntheses and characterization. The stereoselective syntheses of the (R,R)-and the (S,S)-ligands 22 were performed in several steps using the (+)-or (-)-ephedrine methodology, via formation of the chlorophosphaneborane intermediate 26. [18] The key step of the synthesis is the methano bridge formation from the reaction of the carbanion derived from the methylphosphane-borane 27 with the chlorophosphane-borane 26; see Scheme 6, only the (R,R)-version is shown. [18] Thus, the reaction of the (S)-o-anisylchlorophenylphosphane-borane 26 with the MeLi reagent affords the corresponding (R)-methylphosphane-borane 27 with inversion of configuration at the P-centre. After deprotonation of the methylphosphane-borane 27 with nBuLi, reaction with the Scheme 5. Scheme 6.

Intriguing Near-Infrared Solid-State Luminescence of Binuclear Silver(I) Complexes Based on Pyridylphospholane Scaffolds

“…72 At the same time complex [Ag 2 (PyPPh 2 ) 2 ](OTf) 2 with dense crystal packing (the Kitaigorodsky packing index of 70.2%) is described as blue-emissive (λ em 497 nm), suggesting the importance of the presence of the tetrafluoroborate anion. A number of similar binuclear silver(I) complexes with tetrafluoroborate anion bearing different ligands (dppm, 73 or dppm-based, 74 1-methylbenzimidazole diphenylphosphines, 75 pyridyl-containing triazoles, 76 and terpyridines 77 ) demonstrate blue or green emission. Thus, we can hypothesize that there are some requirements in addition to the dense crystal packing, which can be essential for IR luminescence, i.e., the coordination of metal center to both phosphine and pyridyl (or its̀Nheterocycle analogues) groups, Ag•••Ag metallophilic interactions, and the presence of BF 4 anion.…”

Synthesis and Photophysical Properties of Emissive Silver(I) Halogenido Coordination Polymers Composed of {Ag2X2} Units Bridged by Pyrazine, Methylpyrazine, and Aminopyrazine

“…Compared to that of copper­(I) and gold­(I) complexes, the development of luminescent silver­(I) complexes has started only recently; however, several silver complexes exhibiting strong luminescence at room temperature, − thermally activated delayed fluorescence, − thermochromic luminescence, − and stimuli-responsive luminescence , have already been reported. Because the coordination properties and electronic structures of silver­(I) complexes are similar to those of copper­(I) complexes, the ligands affording luminescent copper­(I) complexes have also been exploited to synthesize luminescent silver­(I) complexes. ,− The obtained complexes typically display emission in the near-ultraviolet (UV) or blue region even though the corresponding copper­(I) complexes show colorful emission in the visible region. ,− Because the stability of the 4d orbitals of the silver­(I) center is higher than that of the 3d orbitals of the copper­(I) center, ,− the metal-to-ligand CT ES increases in energy, approaching those of the other ESs, which causes a mixing of the ESs and complicates their emissive ESs, hampering the rational design of a ligand set for luminescent silver­(I) complexes.…”

Betti base derived P-stereogenic phosphine-diamidophosphite ligands with a single atom spacer and their application in asymmetric catalysis

“…In fact, there are only a handful of examples of chiral bisphosphine ligands with a single atom (carbon, oxygen or nitrogen) linker, such as bis-(diphenylphosphino)methane, 13,14 trichickenfootphos (TCFP), 15 MaxPHOS 16–19 which all found application in asymmetric catalysis (Fig. 1a).…”