Bi-, Tetra-, and Hexanuclear Au^I and Binuclear Ag^I Complexes and Ag^I Coordination Polymers Containing Phenylaminobis(phosphonite), PhN{P(OC₆H₄OMe-o)₂}₂, and Pyridyl Ligands

Abstract

The reactions of phenylaminobis(phosphonite), PhN{P(OC6H4OMe-o)2}2 (1) (PNP) with [AuCl(SMe2)] in appropriate ratios, afford the bi-, and mononuclear complexes, 3 IntroductionFor the past few decades there has been continued interest in the chemistry of d 10 metal systems due to the rich photochemical properties, 1 catalytic applications, 2 and use in drug discovery. 3 In addition to a variety of coordination geometries, the short metalmetal contacts, described as "metallophilicity", have been employed in the construction of several macrocyclic molecules and supramolecular architectures via intra-and intermolecular aggregations. 4 The term "aurophilicity" has been introduced to describe The 31 P NMR spectrum of 2 consists of a single peak at 114.3 ppm whereas 3 shows two doublets centered at 112.2 and 133.8 ppm, with a large 2 JPP coupling of 341 Hz. 16 The 1 H NMR spectra of 2 and 3 show single resonances corresponding to the ortho-methoxy groups at 3.82 and 3.71 ppm, respectively. The structure of complex 2 was confirmed by an X-ray structure determination. 6Bi-, tetra-and hexanuclear Au I macrocycles. Complex 2 is a potential precursor for the preparation of various bi-, tetra-and hexanuclear gold(I) macrocycles due to the presence of two highly polar Au-Cl bonds. ligands, we believe that the "rigid short-bite" R2PN(R')PR2 (where R, R' = alkyl or aryl)ligands with bulky substituents around the phosphorus centers will prefer to form thermodynamically favored ring structures instead of forming the polymers. Although these complexes are moderately stable to air, they turn purple after keeping for a long time even under inert atmosphere. Silver(I) DerivativesThe reaction of 1 with AgOTf in a 1:2 mole ratio leads to the formation of a binuclear complex, [Ag2(μ-OTf)2(μ-PNP)] (9), in quantitative yield. In complex 9, the Ag I atoms are bridged by a pair of trifluoromethanesulfonate ions and a PNP ligand so as to provide trigonal planar geometry around the Ag I centers. The displacement of trifluoromethanesulfonate ligands in 9 by two equivalents of 1 afforded a "manxane"-like triply-bridged binuclear complex, [Ag2(μ-PNP)3](OTf)2 (10) as shown in Scheme 3. The 31 P NMR spectrum of complex 9 consists of the A portion of a AA'XX' multiplet centered at 116.7 ppm, whereas the resonance due to 10 appears at 120.8 ppm as a broad singlet. 20The complex, [Ag2(C4H8O)2(µ-PNP)2](ClO4)2 (11) has been prepared by reacting equimolar amount of 1 with AgClO4 in THF. In the 31 P NMR spectrum of complex 11, the resonance appears at 109.2 ppm as a broad doublet due to the complex spin system. In the 1 H NMR spectrum, the resonances corresponding to the coordinated THF molecules appear as two triplets centered at 1.84 and 3.73 ppm with an apparent JHH coupling of 3.6 Hz. The resonance due to the ortho-methoxy and aromatic protons appear in the appropriate regions with the expected relative intensities. Although, the 91 JAgP values for complexes 9 -11 are significantly larger than that observed in analogous phosphine systems, the ...

Weak Interactions between Trivalent Pnictogen Centers: Computational Analysis of Bonding in Dimers X3E···EX3 (E = Pnictogen, X = Halogen)

“…8 Lately, we reported the crystal structure of the aminotetra(phosphine) ligand p-C6H4[N(PCl2)2]2 (1) in which short intermolecular contacts exist only between phosphorus atoms at the terminal NPCl2 moieties (P•••P distance 3.54 Å). 9 The absence of other intermolecular contacts and the slightly undulating two-dimensional sheet structure observed for 1 (see Figure 1) indicate that the weak dispersion interaction has a strong influence in determining the packing of molecules in the solid state. Interestingly, There exists one more crystal structure in the Cambridge Crystallographic Database in which a halogenated tri-coordinate phosphorous moiety (PX2) forms an intermolecular P•••P interaction shorter than the sum of van der Waals radii.…”

“…9 This raises an important question whether the observed P•••P interactions -or E•••E interactions in general-are strong enough to be more widely utilizable in crystal engineering or in building supramolecular 7 assemblies. In order to obtain a conclusive answer, the first theoretical analysis of bonding in doubly bifurcated C2h symmetric X3E•••EX3 dimers (26) is presented herein.…”

Two 1D [CuxIx]-based coordination polymers of tetraphosphine ligands

“…Both compounds were characterized by elemental analysis, IR spectroscopy, 1 H and 31 P{ 1 H} NMR, ESI-MS and thermogravimetric analysis, and their structures were determined by single crystal X-ray diffraction. In 1, [Cu 2 I 2 ] cores are interconnected by dppeda ligands in a l-g 2 :g 2 end-toend mode to form a 1D chain, while in 2 stair-like [Cu 4 I 4 ] cores are linked by dpppda ligands in a unique Z-shaped l-g 2 :g 2 side-by-side mode to produce the other kind of 1D chain.Ó 2009 Elsevier B.V. All rights reserved.In the past decades, the design and synthesis of multi-phosphine ligands have attracted much attention [1-8] due to their versatile ligating capability as well as rich structural chemistry and unique physical and chemical properties of their metal complexes [9][10][11][12][13][14][15][16]. Among the multiphosphine ligands, several tetraphosphine ligands and their metal complexes that showed interesting luminescent properties, catalytic and anticancer performances, have been extensively investigated [17][18][19][20].…”

“…In the past decades, the design and synthesis of multi-phosphine ligands have attracted much attention [1][2][3][4][5][6][7][8] due to their versatile ligating capability as well as rich structural chemistry and unique physical and chemical properties of their metal complexes [9][10][11][12][13][14][15][16]. Among the multiphosphine ligands, several tetraphosphine ligands and their metal complexes that showed interesting luminescent properties, catalytic and anticancer performances, have been extensively investigated [17][18][19][20].…”

“…On the contrary, dpppda in 2 adopts a rare Z-shaped l-g 2 :g 2 side-by-side mode (Scheme 1) to have more side-space to coordinate at the four Cu(I) centers of the [Cu 4 I 4 ] core via four Cu-P bonds. Such a coordination mode was uncommon in the chemistry of tetraphosphines [20] because one tetraphospine ligand usually employs a l-g 2 :g 2 side-by-side mode to bind to only two metal centers [15,30,31].…”