Synthesis, structures and spectroscopic properties of cyclometalated tri-tert-butylphosphine complexes of platinum(II)

Cyclometalated Platinum(II) Complexes Bearing Bidentate O,O′-Di(alkyl)dithiophosphate Ligands: Photoluminescence and Cytotoxic Properties

“…The four-membered "PtSPS" ring exhibits a puckered structure with an almost tetrahedral geometry at the phosphorus atom center. 30,31 On the basis of the previous experiences, the C ∧ N bite angle is considerably smaller than 90°(83.7°) which proves that the C ∧ N chelate is under a strain. 37,38 Photophysical Properties.…”

“…In the aromatic region, a distinctive doublet signal being flanked by platinum satellites is observed at δ = 8.79 ppm which corresponded to the H 2 of ppy ligand ( 3 J HH = 5.7 Hz, 3 J PtH = 43.4 Hz). Moreover, the 31 P{H}NMR spectrum of 2a includes a singlet with platinum satellites at δ = 100.8 ppm with 2 J PtP = 320 Hz. This coupling constant is relevant to the chelating binding mode of O,O′-di(alkyl)dithiophosphate ligands.…”

“…16,18−23 Phosphino alcohols can also give a special puckered P ∧ O ancillary ligand in which the phosphorus head can play role of a strong-field ligand with π-accepting character. 24 Although the use of L ∧ X ancillary ligands in the structure of cycloplatinated(II) complexes is widespread in the literature, 2,6,16,25,26 such complexes bearing S ∧ S chelating systems 27,28 mates 29 or dithiophosphates 30,31 ligands are scarce in the published resources. In contrast, O,O′-di(alkyl)dithiophosphate ligands 32 (S ∧ S) represent a relatively new class of potentially L ∧ X chelating systems (in cycloplatinated complexes) 30,31 which can be easily obtained by deprotonation of O,O′-di(alkyl)dithiophosphoric acid organic compounds.…”

“…24 Although the use of L ∧ X ancillary ligands in the structure of cycloplatinated(II) complexes is widespread in the literature, 2,6,16,25,26 such complexes bearing S ∧ S chelating systems 27,28 mates 29 or dithiophosphates 30,31 ligands are scarce in the published resources. In contrast, O,O′-di(alkyl)dithiophosphate ligands 32 (S ∧ S) represent a relatively new class of potentially L ∧ X chelating systems (in cycloplatinated complexes) 30,31 which can be easily obtained by deprotonation of O,O′-di(alkyl)dithiophosphoric acid organic compounds. 32 Deprotonation reaction from the acidic species gives the corresponding anion that they can be defined by two resonance forms (Scheme 1).…”

“…Some anionic O ∧ O, N ∧ N, and N ∧ O chelates have been employed as the successful examples of L ∧ X ancillary ligands toward the cyclometalated complexes. ,− Phosphino alcohols can also give a special puckered P ∧ O ancillary ligand in which the phosphorus head can play role of a strong-field ligand with π-accepting character . Although the use of L ∧ X ancillary ligands in the structure of cycloplatinated­(II) complexes is widespread in the literature, ,,,, such complexes bearing S ∧ S chelating systems , like dithiocarbamates or dithiophos­phates , ligands are scarce in the published resources.…”