Kupfer(I)‐induzierte Bildung einer „organischen”︁ Sandwich‐Struktur – strukturelle Voraussetzungen für eine Lumineszenz von Zweikernkomplexen [(μ‐Bipyrimidin) {Cu(PR₃)₂}₂]X₂

Abstract

Eine π‐Wechselwirkung Phenyl…︁bpym…︁Phenyl sowie durch Lösungsmittelmoleküle fixierte BF ⊖4‐Gegenionen sind Ursache für die starke Lumineszenz von 1 im Festkörper. Dies folgt daraus, daß sowohl mit einer Reihe anderer Arylphosphanliganden als auch mit PF ⊖6‐ und ClO ⊖4‐Gegenionen sowie in Lösung keine oder nur eine sehr schwache Lumineszenz aus dem Metall‐Ligand‐Charge‐Transfer‐angeregten Zustand beobachtet wird.

Near‐Infrared‐Absorbing Organometallic Diruthenium Complex Intermediates: Evidence for Bridging Anthrasemiquinone Formation and against Mixed Valency

“…non-equivalent hydride ligands) due to the assumed anti-positioning of the CO and Hl igands ( Figures S1 and S2). [11] This central planar section is shielded by four triphenylphosphinel igands with at ypical [31] p/p/p arrangementi nvolving P-phenyl groups and the central plane.I na ccordance with symmetry the CO/Cl ligands are arranged in anti-positions as deduced for Although compounds 3 and 4 do not undergo reversible electron transfers the systems 1 o/ + + and 2 o/ + + could be studied by (spectro)electrochemistry which will be described in the following. [11] This central planar section is shielded by four triphenylphosphinel igands with at ypical [31] p/p/p arrangementi nvolving P-phenyl groups and the central plane.I na ccordance with symmetry the CO/Cl ligands are arranged in anti-positions as deduced for Although compounds 3 and 4 do not undergo reversible electron transfers the systems 1 o/ + + and 2 o/ + + could be studied by (spectro)electrochemistry which will be described in the following.…”

“…[20,22] With [Ru(bpy) 2 ] n and [Ru(acac) 2 ] n complexes of redox-active quinonel igands the g-factor anisotropy Dg has been most useful for studying alternative situations such as A versus B. One is the hyperfine information from nuclei such as 31 Po r 75 As with strong EPR response. One is the hyperfine information from nuclei such as 31 Po r 75 As with strong EPR response.…”

“…with the MÀPb ond(s) parallel to the ligand radical p-system) the 31 Ph yperfinec ouplingm ay become rather large. In those cases [27c] where 31 Pa nd 75 As coupling is resolved the hyperfine values are of comparable magnitude. [27a] Slow rotationalm otion as ac onsequence of the higher mass ( 75 As vs. 31 P) andt he existence of aq uadrupole moment for 75 As with I = 3/2 may contributet ot he insufficient spectralr esolution.…”

“…[23] In this report we can demonstrate that, in addition to the gfactor anisotropy,t wo further sources of information can serve to determine the appropriate valence description. One is the hyperfine information from nuclei such as 31 Po r 75 As with strong EPR response. 31 Ph yperfine splitting has been observed for PR 3 ligands both in radicalc omplexes and mixed-valent species.…”

Zweikernige Bisphosphankupfer(I)-Komplexe mit dem 2,2′-Bipyrimidin-Brückenliganden: Strukturelle Analogie zu „Blauen“ Kupferzentren und Reduktion zu paramagnetischen Spezies / Dinuclear Bis(phosphane)copper(I) Complexes with 2,2′-Bipyrimidine as Bridging Ligand: Structural Analogy to “Blue” Copper Centers and Reduction to Paramagnetic Species

“…Wir berichten hier im Detail [22] über die K ri stallstruktur von [(PPh3)2C u (^: ^4-bPym)Cu(PPh3)2](BF4)2 H 20 • C H 3OH (1), bpym = 2,2'-Bipyrimidin, welche so wohl die Ambivalenz der K oordinationszahl von Cu(I) als auch den Beitrag kooperativer 7r/7r-Wechselwirkungen [23,24] demonstriert. Elektro chemische und ESR-Untersuchungen zur Oxida tion und Reduktion werden für eine Reihe weiterer Zweikern Verbindungen (1) berichtet:…”