The tritopic organometallic ligand trans-MeSC6H4CCPt(PMe3)2(CN)
(L1) was prepared from cis-PtCl2(PMe3)2 and p-ethynyl(methyl
thioether)benzene. Its versatility was shown with the formation of
[CuX(L1)]
n
coordination polymers
(CPs) with CuX salts in MeCN (X = I (CP1), CN (CP2), SCN (CP3)). These CPs were characterized
by X-ray crystallography, thermal gravimetric analysis (TGA), and
IR and Raman spectroscopy. CP1 consists of a 1D head-to-tail
chain formed by tricoordinated −CN–CuI(η2-CC)– linkages, whereas CP2 is
built upon a central (CuCN)
n
zigzag chain
bearing dangling L1s held by −CN–Cu
bonds. Finally, CP3 exhibits 2D sheets secured by Cu–NC–/–(Me)S–Cu
bondings and transversal Cu–S–CN–Cu bridges.
Concurrently, the CPs formed with AgX (X = NO3
– (CP4 and CP5), CF3CO2
– (CP6) PF6
– (CP7)) exhibits 2D sheets with guest molecules (anion,
solvents) inside the tight pores or between layers. These new materials
are emissive: L1 (λ0–0 ∼465
nm), CP1–CP7 (500 < λmax < 620 nm). Their photophysical properties (absorption
and emission spectra, emission lifetimes (∼0.2 < τe < 120 μs), and quantum yields in the solid state
at 77 and 298 K) were analyzed. The various natures of the emissive
excited states were addressed by density functional theory (DFT) and
time-dependent DFT (TDDFT) computations. For CP1, this
state is a triplet halide or pseudohalide to ligand charge transfer 3XLCT (CT = charge transfer; X = I; L = L1) and
for CP2, it is 3XLCT (X = CN; L = L1). However, for CP3, it is 3XLCT (X = SCN;
L = L1). For CP4, the T1 state
is described as a [MeSC6H4(η2-CC)-Ag(NO3)]2 → [Pt]/CCC6H4SMe CT.