scholarly journals Cyclometallated tridentate platinum(ii) arylacetylide complexes: old wine in new bottles

2019 ◽  
Vol 48 (23) ◽  
pp. 5547-5563 ◽  
Author(s):  
Ashanul Haque ◽  
Linli Xu ◽  
Rayya A. Al-Balushi ◽  
Mohammed K. Al-Suti ◽  
Rashid Ilmi ◽  
...  
Keyword(s):  
Luminescent Properties ◽  
Pincer Complexes ◽  
Coordination Site ◽  
Fourth Coordination

Platinum(ii) cyclometallated pincer complexes with an alkynyl ligand in the fourth coordination site display excellent luminescent properties. By manipulation of the pincer and the alkynyl ligand their luminescence can be fine-tuned for opto-electronic applications.

Ligand-modulated ring-expansion

2019 ◽  
Vol 55 (9) ◽  
pp. 1245-1248
Author(s):  
Veronica Carta ◽  
Miguel A. Soto ◽  
Mark J. MacLachlan
Keyword(s):  
Ring Opening ◽  
Ring Expansion ◽  
Coordination Site ◽  
Ring Expansion Reaction ◽  
Bulky Ligand ◽  
Fourth Coordination

An unstrained metal-containing macrocycle was ring-expanded by a ring-opening metathesis strategy, leading to the formation of a bimetallic dimeric macrocycle. The reaction is driven by coordination of a bulky ligand, 2,6-lutidine, on the fourth coordination site of the palladium center. In the absence of metal, or with a less bulky ligand, the ring-expansion reaction does not proceed.

scholarly journals Synthesis & Xray structures of Rare Pentacoordinate Pincer Complexes of Ni(II)

2014 ◽  
Vol 70 (a1) ◽  
pp. C916-C916
Author(s):  
Berline Mougang-Soume ◽  
Davit Zargarian
Keyword(s):  
Organometallic Chemistry ◽  
Materials Science ◽  
Catalytic Reactions ◽  
Pincer Complexes ◽  
Substrate Uptake ◽  
Major Focus ◽  
Pincer Ligand ◽  
The Past ◽  
Coordination Site

Pincer complexes have been a major focus in organometallic chemistry over the past four decades due to their important potential in catalysis and materials science. In the case of pincer complexes of d8 metals, a growing number of charge-neutral and cationic derivatives featuring hydrides, alkyls, and other reactive moieties have been shown to catalyze important transformations. Regarding the mechanisms of these catalytic reactions, an important issue that remains unresolved concerns the type of intermediates formed upon substrate uptake, namely: A: Do substrates displace one or more hemi-labile donor moieties of the pincer ligand? Or B: Does the substrate occupy a fifth coordination site while the pincer ligand remains intact (Scheme 1)? In this presentation, Xray crystallography is used to describe the influence of the substitue on the 18-electron species based on POCN-Ni precursors. These new diamagnetic complexes are proposed as models for the intermediates that might be involved in catalytic reactions promoted by this family of complexes (Scheme 2).

Cadmium complexes of the tripodal [Te(N-t-Bu)3]2– dianion and the HgCl2 adduct of a tellurium diimide dimer

2003 ◽  
Vol 81 (11) ◽  
pp. 1307-1314 ◽  
Author(s):  
Tristram Chivers ◽  
Gabriele Schatte
Keyword(s):  
Nitrogen Atom ◽  
Key Words ◽  
Ion Pair ◽  
The Other ◽  
Cadmium Complexes ◽  
Coordination Modes ◽  
Coordination Site ◽  
Different Types ◽  
Cl Atoms ◽  
Fourth Coordination

The reactions of CdCl2 or HgCl2 with {Li2[Te(N-t-Bu)3]}2 in n-hexane–THF give rise to two distinctly different types of product. In the former case the complexes [Li(THF)x][(CdCl)3{Te(N-t-Bu)3}2] (7a (x = 4), 7b (x = 3)) are obtained. The tetrasolvated complex 7a is a solvent-separated ion pair. The trisolvated complex 7b is a contact ion pair in which the fourth coordination site at the Li+ centre is occupied by one of the Cl ligands of the anion. The polycyclic anion in 7a and 7b is comprised of two tripodal [Te(N-t-Bu)3]2– dianions that exhibit different coordination modes to the three CdCl+ units. One ligand is N,N′-chelated to all three metal centres, and each nitrogen atom bridges two Cd atoms, whereas the other is bonded in a tris-N-monodentate fashion in 7b. In 7a there is an additional weak Cd-N interaction. The reaction of HgCl2 with {Li2[Te(N-t-Bu)3]}2 produces the adduct [t-BuNTe(µ-N-t-Bu)2TeN-t-Bu]HgCl2 (8), in which the dimeric tellurium diimide ligand in its cis(exo,exo) configuration is N,N′-chelated to mercury. Polymeric strands parallel to the b axis are formed by weak Te•••Cl interactions (3.5248(16) Å, 3.5876(15) Å) involving both Cl atoms, but only one Te atom of the ligand. Key words: imido ligands, cadmium, mercury, tellurium.

Solvothermal fabrication and luminescent properties of nanoLuAG:Ce phosphors

2014 ◽  
Vol 9 (1) ◽  
pp. 60-63 ◽  
Author(s):  
Lin Xing ◽  
Lianghui Qu ◽  
Qing He ◽  
Tong B. Tang ◽  
Linfeng Yang
Keyword(s):  
Luminescent Properties

Effect of Hydrated Metal Salts on the Coordination Product of Cobalt(II) halide and PNP Type Ligand, 2,6-bis(di-tertbutylphosphinomethyl) pyridine

2018 ◽  
Author(s):  
Tasneem Siddiquee ◽  
Abdul Goni
Keyword(s):  
Metal Salts ◽  
Molar Ratio ◽  
Pincer Complexes ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Pincer Ligand ◽  
Tetrahedral Geometry ◽  
X Ray ◽  
Distorted Tetrahedral Geometry ◽  
Cobalt Center

Chemical treatment of CoX<sub>2</sub><b><sup>. </sup></b>6H<sub>2</sub>O (X = Cl, Br, I) with the potentially tridentate PNP pincer ligand 2,6-bis(di-<i>tert</i>-butylphosphinomethyl)pyridine in 1:1 molar ratio results in cobalt(II) halide-PNP pincer complexes. The effect of the hydrated metal source on molecular structure and geometry of the complexes was studied by single crystal X-ray diffraction analysis. The complexes are neutral and the cobalt center adopts a penta-coordinate system with potential atropisomerization. Within the unit cell there are two distinct molecules per asymmetric unit. One of the two phosphorus atoms in the PNP ligand was observed to be partially oxidized to phosphinoxide. Disorder in the structure reflects a mixture of square pyramidal and distorted tetrahedral geometry.

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