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Compounds NBu4[Pt(C^C*A/B/C)(CN)2] (HC^C*A = 1-(4-(ethoxycarbonyl)phenyl)-3-methyl-1H-imidazol-2-ylidene 1, HC^C*B = 1-(4-cyanophenyl)-3-methyl-1H-imidazol-2-ylidene 2, HC^C*C = 1-(3,5-dichlorophenyl)-3-methyl-1H-imidazol-2-ylidene 3) and NBu4 [Pt(C^C*A/B/C)(13CN)2] (1'-3') were synthesized by addition of KCN (or K13CN) to freshly prepared species [Pt(C^C*A/B/C)(NCCH3)2]ClO4, in a 2:1?M ratio. Single crystal X-ray structures of 1-3 showed the absence of intermolecular π-π and Pt-Pt interactions. The 195Pt{1H} NMR data of 1-3 were obtained and compared with those of the related compounds NBu4[Pt(C^N)(CN)2] (C^N?=?benzoquinolate, bzq; phenylpyridinate, ppy). They indicate that the electronic density on the Pt center is larger for NBu4[Pt(C^C*A/B/C)(CN)2] (1-3) than for NBu4[Pt(C^N)(CN)2], which has been proved through NBO charge distribution analysis. Compounds 1 and 2 resulted to be rather good blue-emitters with their emissions arising mainly from 3IL [π(NHC) → π*(NHC)] excited states with little 3MLCT [5d(Pt) → π*(NHC)] character. The emission of 2 in PMMA film render PLQY (Φ) of 70% and Commission Internationale de L'Eclairage (CIE) coordinates (0.15, 0.19) highly close to the optimal ones for blue emitters (0.15, 0.15).
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