Luminescent Pt^II−M^I (M = Cu, Ag, Au) Heteronuclear Alkynyl Complexes Prepared by Reaction of [Pt(C⋮CR)₄]^2- with [M₂(dppm)₂]²⁺ (dppm = Bis(diphenylphosphino)methane)

Abstract

A series of PtM, PtM2, and Pt2M3 (M = Cu, Ag, Au) heteronuclear alkynyl complexes, synthesized by reaction of the tetraalkynylplatinate(II) complexes [Pt(C⋮CR)4]2- with [M2(μ-dppm)2]2+ (dppm = bis(diphenylphosphino)methane), were characterized by elemental analyses, ESI-MS, 1H and 31P NMR spectroscopy, and X-ray crystallography for 5−13. The PtII and MI centers are linked doubly and singly by dppm in the PtM and PtM2 complexes, respectively. The Pt2Ag3 complex 13 is composed of two PtAg units associated with another Ag center by acetylide η 2 (π) coordination. Strong Pt−M bonding interactions are operative, in view of their rather short distances (2.7−3.0 Å). Compounds 1−13 emit strongly in the solid state at 298 and 77 K with lifetimes in the microsecond range, indicating spin-forbidden triplet excited states. They also exhibit moderate photoluminescence in degassed dichloromethane at 298 K. The emission energy in the solid state decreases with an increase in the electron-donating ability of the R substituents, implying that the emissive origin is probably substantial ligand-to-cluster [RC⋮C→PtM] LMMCT transitions, in view of the Pt−M interactions.

Self‐Assembly of Supramolecular Luminescent AuI–CuI Complexes: “Wrapping” an Au6Cu6 Cluster in a [Au3(diphosphine)3]3+ “Belt”

“…Growing attention to alkynyl complexes of coinage metals, stimulated by their intriguing photophysical properties, [1][2][3][4][5] has substantially focused on polynuclear homo-and heterometallic compounds. [2,[4][5][6][7][8][9][10] The versatile bonding mode of alkynes and metallophilic interactions resulted in the synthesis of numerous cluster complexes which display different structural motifs and emission properties. [5,6,9,11] However, in most cases assembly of the complexes occurs in an uncontrolled way [6,7,11] and therefore it is a challenge to find a synthetic approach which would allow directed modification of the structural and electronic properties of these compounds.…”

“…[2,[4][5][6][7][8][9][10] The versatile bonding mode of alkynes and metallophilic interactions resulted in the synthesis of numerous cluster complexes which display different structural motifs and emission properties. [5,6,9,11] However, in most cases assembly of the complexes occurs in an uncontrolled way [6,7,11] and therefore it is a challenge to find a synthetic approach which would allow directed modification of the structural and electronic properties of these compounds. One of the most attractive features of supramolecular construction is the possible tuning of the luminescent behavior through changes in the electron richness of the alkyne ligands by p coordination to different metal ions.…”

Luminescent Heteropolynuclear Complexes of 3,5‐Dimethylpyrazolate [Pt2Au2M2(Me2pz)8] (M=Ag, Cu) Showing the Synergistic Effect of Three Transition Elements in the Excited State

“…[12] The successful control of emission energies, that is, the successful control of the nature of the singly occupied molecular orbitals (SOMOs), by the change of the incorporated coinage metal ions, which have different orbital energies corresponding to the nature of them, was attributed to the fact that the emissive states of [Pt 2 M 4 A C H T U N G T R E N N U N G (m-Me 2 pz) 8 ] (M= Cu (1), Ag (2)) are 3 (Cu(d)!Pt 2 Cu 4 ) and 3 (Pt 2 !Pt 2 Ag 4 ), respectively. The emission was assigned to the transition from the in-phase combination of 6p(Pt) and 4p (Cu) to the dp(Cu) orbital localized on one of the four Cu atoms for the Pt À Cu complex and that from the in-phase combination of 6p(Pt) and 5p(Ag) to the dd(Pt) non-bonding orbital for the Pt À Ag complex.…”

“…One of the best probes to investigate the metal-metal interactions is luminescence, because it is very sensitive to the change of the energies of ground and excited states. Much effort has been devoted to the study of the photophysical properties of heteropolynuclear complexes, [1][2][3][4][5][6][7][8][9][10][11] though these studies are limited to the complexes composed of two transition elements and ligands. It is thus very interesting to study the photophysical properties arising from the metal-metal interactions among three transition elements.…”

A Luminescent Heteronuclear Cluster Featuring an Unusual Cu6 Boat‐Shaped Core Assembled by Two Dialkynyl‐Cycloplatinated Units

“…[1,7,8,10,12,[14][15][16][17][18][19][20][21] In this area, considerable interest has been paid to Pt II -M I (M = Cu, Ag, Au) heterometallic alkynyl complexes due to their rich structural topology [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] and interesting spectroscopic and optical properties. [1,14,17,[41][42][43][44][45][46][47][48][49][50][51][52] In these systems, luminescence behavior is strongly influenced by the modification of the electron density of the CϵCR units through the variation of the R substituents, η 2 -M alkynyl bonding and also by metallophilic interactions (Pt···Pt, Pt···M, M···M). [1,<...>…”