Temperature and magnetic field effects on the luminescence of thallium(1+) tetracyanoplatinate(1-)

Tri-[Pt2Tl]3- and Polynuclear Chain [Pt−Tl]∞- Complexes Based on Nonbridged PtII−TlI Bonds: Solid State and Frozen Solution Photophysical Properties

“…In contrast, the emission and the lifetime of the related [Tl 2 Pt(CN) 4 ] complex reported by Balch and co-workers 9 are temperature dependent. In particular, the lifetime lengthens considerably at lower temperatures (1.4 μs, 77 K; 77 μs, 1.4 K),9b and at ≤77 K, a second emission red band clearly resolves (at 1.4 K, two bands at 457 and 577 nm were observed) 9b. On the basis of previous assignments, the emission in 1 is attributed to the Pt−Tl chromophore and assigned to a MM‘CT transition.…”

“…The room-temperature absorption spectra of the three complexes ( 1 − 3 ) are essentially identical (See Figure S2 in Supporting Information). A low-energy absorption at 350 nm, which is absent in the precursor, seems to be characteristic of the presence in solution of the [TlPtR 4 ] - system and, on the basis of previous assignments in d 8 −Tl I systems, 6d,,10a,12g, is tentatively attributed to a spin- and symmetry-allowed σ*−σ system with some metal-to-metal (Pt−to−Tl) charge-transfer (MM‘CT) character. 6d,12g, In the solid state, the Pt···Tl bonding contacts in both 1D chain complexes ( 2 and 3 ) are observed as a broad absorption, spanning the range from ca. 375 to 700 nm (Supporting Information, Figure S3).…”

“…Special interest is also currently devoted to the photophysics of discrete heteronuclear complexes stabilized by polar metal···metal bonds. 3a, However, compared to the numerous reports of hetero bi- and trimetallic complexes involving Pt II → M donor acceptor bonds, 6a, the related extended mixed-metal systems containing unsupported platinum−metal bonds are scarce . For compounds containing Pt−Tl bonds, since the luminescent discrete complex, trans -[PtTl 2 (CN) 4 ], was reported by Balch et al, several types of bi- (Pt 0,II −Tl I , Pt II −Tl III ), ,12b tri- (Pt 2 II,0 −Tl I , Pt II −Tl 2 I , Pt 2 II −Tl II ), and polynuclear complexes 12 have been structurally characterized. However, as far as we know, only two examples of polymeric Pt−Tl species have been reported: an extended chain { trans , trans , trans -[PtTl 2 R 2 (C⋮C t Bu) 2 ](acetone) 2 } x formed by octahedral “PtTl 2 R 2 (C⋮C t Bu) 2 ” fragments linked through weak alkynyl−thallium interactions 13a and two polymorphs of the complex [Tl I (C 4 H 9 N 4 )Pt II (CN) 2 ] (red and yellow), which differ in the nature of the metallophilic Pt····Tl interactions.…”

Luminescent Amidate-Bridged One-Dimensional Platinum(II)−Thallium(I) Coordination Polymers Assembled via Metallophilic Attraction

“…The emission from d 8 −s 2 mixed metal complexes is well-established. The d 8 −s 2 bond interaction is a known reason for the photoluminescence in Pt−Tl complexes . Significant overlap between the filled 5d z 2 orbitals of platinum and the empty 6p orbitals of thallium is responsible for the emissive behaviors.…”

New Class of Oligonuclear Platinum−Thallium Compounds with a Direct Metal−Metal Bond. 2. Structural Characterization of the Complexes

“…The interest in direct metal−metal linkage between platinum and thallium atoms was initiated by Nagle and Balch, who reported six-coordinated platinum in the structure of trans -Tl 2 Pt(CN) 4 which does not possess the usual for platinum(II) tetracyano salts Pt−Pt linked columnar structure but involves two covalent Pt−Tl bonds . The unusual structure and strong luminescence exhibited by this compound initiated several studies of its electronic properties. − Later, a Pt−Tl bond was also found in such compounds as the binuclear [Tl(crown-P 2 )Pt(CN) 2 ](NO 3 ) and in two trinuclear Pt−Tl−Pt species: cis -[Tl{(1-MeT) 2 Pt(NH 3 ) 2 } 2 ](NO 3 )·7H 2 O and (NBu 4 ) 2 [Tl{Pt(C 6 F 5 ) 4 } 2 ] …”