Synthesis, crystal structures and reactions of sila- and germa-β-diketiminates

Synthesis and structures of 3-sila-β-diketiminato complexes of the coinage metals

“…2 with selected geometrical parameters. The six atoms Li, N(1), C(13), Si(1), C(4) and N(2) of the Li[{N(R)C(Ar)} 2 SiR] moiety adopt the boat conformation, as previously found for B [4], C1 [7]. Its Si(1) and Li atoms act as a bridge to the Cu and I atoms, respectively.…”

“…Its Si(1) and Li atoms act as a bridge to the Cu and I atoms, respectively. The endocyclic parameters of the boat are somewhat similar to those in L as shown by the following data for L: 9(2)°, C(4)-Si(1)-C(13) 108.8(1)°; and the dihedral angles between the N(1)C(13)-C(4)N(2) plane and the N(1)LiN(2) and C(13)Si(1)C(4) planes are 53.7(1)°and 28.4(1)°, respectively [7], which Table 1 Selected endocyclic geometric parameters for 1, four Cu I amidinates and a Cu I 1-azaallyl (R = SiMe 3 ) (6) 1.275 (7), 1.288 (7) 1.740 (5), 1.753 (5) 106.3(2), 110.9(2) 111.5(4), 114.4 (5) 132.1(4), 133.9(4) When the silver reaction was carried out using an equimolar portion of the two reagents, approximately one half of the unreacted [AgI(PPh 3 ) 3 ] was recovered. A freshly prepared sample of 3 or 4 in C 6 D 6 gave 1 H NMR spectra showing the appropriate relative intensities for signals corresponding to the ligand; and the 29 Si spectra of 3 revealed coupling of the 29 Si nucleus to both 107 Ag and 109 Ag, as expected from the molecular structure shown for crystalline 3.…”

“…Compound B has been the source of the derivatives C1 [6], C2 [7], D [6], E1 to E5 [7], G [7] and H [8], as shown in Scheme 1. X-ray structural data are available for [Li{(N(R)@C(Ar)) 2 SiR}(NCAr) 2 ] [4], [Li{(N(R)@C(Ar)) 2 -SiR}(NCAr)] [7], C1 [6], C2 [7], D [6], E2 [7], E3 [7], E5 [7], F [7] and H [8]. Two further crystalline magnesium 3-sila-bdiketiminates have been reported: I from [Mg(SiR 3 ) 2 (thf) 2 ] [9] and 2ArCN, and J from I and Me 3 SiOTf [8].…”

“…The NMR spectra were recorded at 298 K using a Bruker DPX 300 (300. [30]; the synthesis of [Li{(N(R)C(Ar)) 2 -SiR}(thf) 2 ] (B) was described previously [4,7]. Each of the compounds 1-4 in benzene slowly decomposed yielding a metallic precipitate; 1 and 2 were sufficiently robust to be sent away for microanalysis (Medac Ltd., Brunel University).…”

“…ORTEP diagram of the molecular structure of 4 with thermal ellipsoids drawn at 20% probability level. SiR}(NCAr)] (L) [7], while parameters associated with the atoms I and Ag (3) or Au (4) are to be found in Table 4. The Au-Si distance in 4 may be compared with the 2.356(2) Å in [Au(SiR 3 )(PMePh 2 )] [22]; Ag-Si-containing compounds were not found in the Cambridge Crystallographic Data Base [23].…”