Coinage Metal Complexes of Bis(quinoline‐2‐ylmethyl)phenylphosphine‐Simple Reactions Can Lead to Unprecedented Results

Abstract

The different coordination behavior of the flexible yet sterically demanding, hemilabile P,N ligand bis(quinoline‐2‐ylmethyl)phenylphosphine ( bqmpp ) towards selected Cu I , Ag I and Au I species is described. The resulting X‐ray crystal structures reveal interesting coordination geometries. With [Cu(MeCN) 4 ]BF 4 , compound 1 [Cu 2 (bqmpp) 2 ](BF 4 ) 2 is obtained, wherein the copper(I) atoms display a distorted square planar and square pyramidal geometry. The steric demand and π‐stacking of the ligand allow for a short Cu⋅⋅⋅Cu distance (2.588(9) Å). Cu I complex 2 [Cu 4 Cl 3 (bqmpp) 2 ]BF 4 contains a rarely observed Cu 4 Cl 3 cluster, probably enabled by dichloromethane as the chloride source. In the cluster, even shorter Cu⋅⋅⋅Cu distances (2.447(1) Å) are present. The reaction of Ag[SbF 6 ] with the ligand leads to a dinuclear compound ( 3 ) in solution as confirmed by 31 P{ 1 H} NMR spectroscopy. During crystallization, instead of the expected phosphine complex 3 , a tris(quinoline‐2‐ylmethyl)bisphenyl‐phosphine ( tqmbp ) compound [Ag 2 (tqmbp) 2 ](SbF 6 ) 2 4 is formed by elimination of quinaldine. The Au(I) compound [Au 2 (bqmpp) 2 ]PF 6 ( 5 ) is prepared as expected and shows a linear arrangement of two phosphine ligands around Au I .

Trigonal Planar Au@Ag3Clusters Showing Exceptionally Fast and Efficient Phosphorescence in Violet to Deep‐Blue Region

“…By contrast, each of two Ag atoms of 3d is weakly associated with monodentate NO 3 − anion ( d Ag–O ≈2.66 Å), and the third Ag center is associated with two NO 3 − anions ( d Ag–O ≈2.49 Å). Taken together, the geometric parameters of dative Au−P/Ag−N bonds and also metallophilic Au⋅⋅⋅Ag contacts in 3a – d are comparable with those of the known Au(I) and Ag(I) clusters [21–24] . It should be underlined that the Au@Ag 3 kernel found in 3a – d is very rare: so far it was found only in {AuAg 3 [(Ph 2 P) 3 CH] 2 }(ClO 4 ) 4 , [21] wherein the Au⋅⋅⋅Ag contacts, however, are much longer (3.106–3.147 Å) that those of 3a – d .…”

“…The X-ray-derived structures of 1a, 2a/2b, and 3a-d are depicted in Figure 1 (in more detail, see Figures S1-S7 Taken together, the geometric parameters of dative AuÀ P/ AgÀ N bonds and also metallophilic Au•••Ag contacts in 3a-d are comparable with those of the known Au(I) and Ag(I) clusters. [21][22][23][24] It should be underlined that the Au@Ag 3 kernel found in 3a-d is very rare: so far it was found only in {AuAg 3 [(Ph 2 P) 3 CH] 2 }(ClO 4 ) 4 , [21] wherein the Au•••Ag contacts, however, are much longer (3.106-3.147 Å) that those of 3a-d.…”

Coinage metal complexes of multidentate Pacman phosphane ligands

“…0.33 Å to d(P-P) = 4.566(2) Å, which is in line with the typical flexibility of Pacman ligands. However, the Au-P distances fall within the normal range 12 (2.286(1) Å, Table 1). Additionally, the distances between the gold and the imine nitrogen atoms are slightly shorter than the sum of the van der Waals radii of 3.21 Å 13 (3.043(3)-3.071(3) Å, Table 1).…”

“…At the same time, the Ag–P distance is slightly longer compared to d (Au–P) (2.382(1) Å, Table 1), but still within the typical range for such complexes (2.4 Å). 12 The distortion is further increased in the copper complex 1Cu + (Fig. 2).…”

“…The distances between the imine nitrogen atoms N3 and N7 and the copper are further shortened compared to 1Ag + (2.120(2) Å, Table 1) and therefore fall within the range of a nitrogen–copper bond (2.1 Å). 12 Together with the two phosphorus atoms, the coordination environment around the copper can be described as a distorted tetrahedron.…”