Murray Niamh S, Keller Sarah, Constable Edwin C, Housecroft Catherine E, Neuburger Markus, Prescimone Alessandro
Department of Chemistry, University of Basel, Spitalstrasse 51, CH-4056 Basel, Switzerland.
Dalton Trans. 2015 Apr 28;44(16):7626-33. doi: 10.1039/c5dt00517e.
The first examples of Cu(N^N)(POP) complexes (POP = bis(2-(diphenylphosphino)phenyl)ether) in which the N^N domain is a 2,2':6',2''-terpyridine (tpy) ligand have been prepared and characterized; N^N = tpy, 5,5''-dimethyl-2,2':6',2''-terpyridine (1), 4′-(4-tolyl)-2,2′:6′,2′′-terpyridine (2), 4′-(4-npropoxyphenyl)-2,2′:6′,2′′-terpyridine (3) and 4′-(4-nbutoxyphenyl)-2,2′:6′,2′′-terpyridine (4). In solution, the tpy domain in each [Cu(N^N)(POP)][PF6] complex is C2-symmetric, consistent with either tridentate coordination or a low energy dynamic process involving bidentate ligands; for [Cu(2)(POP)][PF6] and [Cu(4)(POP)][PF6], the (1)H NMR spectra showed negligible change between 295 and 210 K. The single crystal structures of [Cu(tpy)(POP)][PF6] and [Cu(4)(POP)][PF6] are presented. The asymmetric unit of [Cu(tpy)(POP)][PF6] contains two independent cations; in one the tpy ligand is tridentate and in the other, it is bidentate with the non-coordinated pyridine ring facing the Cu atom (Cu···N = 3.146(1) Å). In contrast, the solid-state structure of [Cu(4)(POP)][PF6] features a Cu(4)(POP) cation containing a bidentate tpy-domain with the non-coordinated pyridine ring oriented with the N-atom facing away from the Cu atom; this conformation may be associated with inter-cation NHC non-classical hydrogen bonds. The photophysical properties of [Cu(N^N)(POP)][PF6] with N^N = tpy or 1–4 are described. In the solid state at room temperature, the compounds are poorly emissive. In solution, the emission behaviour is consistent with ligand dissociation. This is supported by (1)H and (31)P NMR spectroscopic data which show POP and Cu(POP)2 in solutions of aged samples; mass spectrometric data are consistent with the formation of Cu(N^N)2 in these samples.
已制备并表征了Cu(N^N)(POP)配合物（POP = 双(2-(二苯基膦基)苯基)醚）的首个示例，其中N^N域为2,2':6',2''-三联吡啶（tpy）配体；N^N = tpy、5,5''-二甲基-2,2':6',2''-三联吡啶（1）、4′-(4-甲苯基)-2,2′:6′,2′′-三联吡啶（2）、4′-(4-正丙氧基苯基)-2,2′:6′,2′′-三联吡啶（3）和4′-(4-正丁氧基苯基)-2,2′:6′,2′′-三联吡啶（4）。在溶液中，每个[Cu(N^N)(POP)][PF6]配合物中的tpy域具有C2对称性，这与三齿配位或涉及双齿配体的低能量动态过程一致；对于[Cu(2)(POP)][PF6]和[Cu(4)(POP)][PF6]，(1)H NMR光谱显示在295至210 K之间变化可忽略不计。给出了[Cu(tpy)(POP)][PF6]和[Cu(4)(POP)][PF6]的单晶结构。[Cu(tpy)(POP)][PF6]的不对称单元包含两个独立的阳离子；在一个中tpy配体是三齿的，而在另一个中，它是双齿的，未配位的吡啶环朝向Cu原子（Cu···N = 3.146(1) Å）。相比之下，[Cu(4)(POP)][PF6]的固态结构具有一个Cu(4)(POP)阳离子，其包含一个双齿tpy域，未配位的吡啶环的N原子背离Cu原子取向；这种构象可能与阳离子间的NHC非经典氢键有关。描述了N^N = tpy或1 - 4的[Cu(N^N)(POP)][PF6]的光物理性质。在室温下的固态中这些化合物发射性较差。在溶液中，发射行为与配体解离一致。这得到了(1)H和(31)P NMR光谱数据的支持，这些数据显示老化样品溶液中有POP和Cu(POP)2；质谱数据与这些样品中Cu(N^N)2的形成一致。
