om8b00461_si_001.docx (3.55 MB)
Highly Emissive Cycloplatinated(II) Complexes Obtained by the Chloride Abstraction from the Complex [Pt(ppy)(PPh3)(Cl)]: Employing Various Silver Salts
Version 2 2021-10-04, 12:35
Version 1 2018-08-30, 12:49
journal contribution
posted on 2018-08-30, 12:49 authored by Hamid R. Shahsavari, Reza Babadi Aghakhanpour, Mahshid Nikravesh, John Ozdemir, Mohsen Golbon Haghighi, Behrouz Notash, M. Hassan BeyzaviIn the present investigation, the
precursor complex [Pt(ppy)(PPh3)(Cl)], 3,
ppy = 2-phenylpyridinyl, undergoes
the chloride abstraction reaction using various AgX (X = PF6, BF4, NO3 and CH3COO) salts. Depending
on the nature of anions in AgX salts (coordinating or noncoordinating),
the products can be neutral or ionic. In the cases of NO3 and CH3COO, they can be coordinated to the Pt center
so that the neutral complexes [Pt(ppy)(PPh3)(NO3)], 4a, and [Pt(ppy)(PPh3)(CH3COO)], 4b, are formed. In contrast, the ionic complexes
[{Pt(ppy)(PPh3)(CH3CN)}PF6], 5a, and [{Pt(ppy)(PPh3)(CH3CN)}BF4], 5b, can be generated when the AgPF6 ([{Ag(CH3CN)4}PF6]) or AgBF4 ([{Ag(CH3CN)4}BF4]) salts
are used in which the PF6 and BF4 stand as counteranions.
In these two complexes, CH3CN fills the empty ligand position
which can be present as solvent or ligand in the initial silver salts.
The structures of the new complexes were accurately deduced from the
multinuclear (1H, 31P{1H}, 195Pt{1H}) NMR spectroscopy and further authenticated by
X-ray crystallography. Interestingly, the complexes are green emitters
under various states and temperature conditions for which nonchelating
L/X (PPh3/NO3 or PPh3/CH3COO) and L/L (PPh3/CH3CN) ancillary ligands
exist in the structure of cycloplatinated(II) complexes. The photophysical
properties of these new complexes, supported by density functional
theory (DFT) and time-dependent DFT (TD-DFT) calculations, were investigated
by photoluminescence and UV–vis spectroscopies.