Exploring the Transphobia Effect on Heteroleptic NHC Cycloplatinated Complexes

Abstract

The synthesis of 1-(4-cyanophenyl)-1H-imidazol(1) has been carried out by an improved method. Then, its corresponding imidazolium iodide salt, 2, has been used to prepare the N-heterocyclic carbene (NHC) cycloplatinated compound [{Pt(µ-Cl)(C^C*)} 2 ] (4) (HC^C*-κC*=1-(4-cyanophenyl)-3-methyl-1H-imidazol-2-ylidene)

Highly efficient platinum-based emitters for warm white light emitting diodes

“…These values are in agreement with those observed for other compounds containing these same ''(R-C^C*)Pt'' (R-C = Naph, R = CO 2 Et) moieties. 26,27,30 Contrary to what has been observed throughout the UV-vis absorption and TD-DFT sections, the emission energy of the Naph^C* derivatives (1A-3A) does not depend on the P^P ligand, whereas those of their B (1B-3B) counterparts clearly do (see Fig. S12, ESI †).…”

“…The larger 1 J Pt,P value corresponds to the P atom located trans to the N-heterocyclic carbene (C1), whose trans influence is smaller than that of the aromatic C atom (C6). 30 The 195 Pt{ 1 H} NMR spectrum of each compound shows a doublet of doublets due to the coupling of the Pt center to two inequivalent P atoms (see Fig. S3, ESI † and Table 1).…”

The Use of Cyclometalated NHCs and Pyrazoles for the Development of Fully Efficient Blue PtII Emitters and Pt/Ag Clusters

“…Species B result also from the reaction of A with 2 equiv of RpzH. The cis ‐(C*,Cl) and trans ‐(C*,Cl) isomers appeared in ratios of 14:1 and 16:1 for 4‐MepzH and pzH respectively (see Figure S8) and were identified on the bases of the 1 H NMR . Species B would be formed from 2 a / 3 a by displacement of a RpzH ligand by the Cl − , and co‐exist in solution with 2 a / 3 a in a dynamic equilibrium, such as the represented in Scheme .…”

“…The small bite angle of the cyclometalatedl igand [80.17(10)8]t ogether with the PtÀC6 and PtÀC1(C*) distances are similar to those found in other five-membered metalocycles of Pt II with NHC ligands. [4a,d] These distances evidence the low trans influence of the 3,5-Me 2 pzH ligandss ince them are shorter than those observed in complexes sucha s[ Pt(NC-C^C*)(P P)]PF 6 (P^P = diphenylphosphino-ethane) [12] and [Pt(R-C^C*)(CNR') 2 ]PF 6 (R = CN, CO 2 Et;R ' = Xyl, tBu). [4b] The PtÀNb ond distances are rather long and similart ot hose found in complex cis-[Pt(CC) 2 (Hdmpz) 2 ], [8] which is in agreement with the high trans influence of both Ca toms (C1 and C6) of the EtO 2 C-C^C*-kC,C* ligand,m ainly the s-bonded C Ar (C6).…”

“…The cis-(C*,Cl) and trans-(C*,Cl) isomers appeared in ratios of 14:1 and 16:1 for 4-MepzH andp zH respectively (see Figure S8) and were identified on the bases of the 1 HNMR. [12] Species B would be formed from 2a/3a by dis-placementofaRpzH ligand by the Cl À ,and co-exist in solution with 2a/3a in ad ynamic equilibrium, such as the represented in Scheme 3. In agreement with this, addition of 4-MepzH/pzH to as olutionofc ompound 2a/3a in CD 2 Cl 2 shifts this equilibrium to the left and the signals attributedt oB disappear (see…”