Ni(II) complexes with thioether-functionalized silylamide ligands. Synthesis and crystal structures of [Ni{Me₂Si(N-C₆H₄-2-S-t-Bu)₂}], [Ni{Ph₂Si(N-C₆H₄-2-SMe)₂}] and [Ni{Ph₂Si(N-C₆H₄-2-SPh)₂}]

Abstract

Thioether-functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with R=Me, Ph and R′=t-Bu, Me, Ph were synthesized from the corresponding dichlorosilanes R2SiCl2 and lithiated aniline derivatives LiNH-C6H4-2-SR′. Treatment of the functionalized aminosilanes R2Si(NH-C6H4-2-SR′)2 with two eq. of n-BuLi and subsequent reaction with nickel(II) halides NiX2 (X=Cl, Br) or [Ni(acac)2(TMEDA)] led to the formation of the Ni(II) complexes [Ni{R2Si(N-C6H4-2-SR′)2}]. The X-ray single-crystal structure determinations of the nickel complexes revealed that the thioether-functionalized silylamides R2Si(NC6H4-2-SR′)22− act as tetradentate ligands. The nickel atoms exhibit a distorted square-planar coordination with Ni–N and Ni–S bond lengths in the range of 186.4(3)–186.9(2) pm and 217.5(1)–221.5(1) pm, respectively.

Dinuclear Molybdenum(II) Complexes with Thioether Functionalized Silylamide Ligands

“…The Si–N distances are in a typical range of 171.0(3) to 173.1(3) pm, which is in accordance with observations in other aminosilanes [e.g. : Me 2 Si(NHC 6 H 4 ‐2‐SPh) 2 : 173.2(2) pm; Me 2 Si(NHC 6 H 4 ‐2‐S t Bu) 2 : 172.3(2) pm] and silylamide complexes [e.g. : Tl 2 Me 2 Si(NHC 6 H 4 ‐2‐SPh): 172(1)–173(1) pm, Ag 2 {Me 2 Si(NHC 6 H 4 ‐2‐SPh) 2 }(PMe 3 ) 2 : 171.2(4)–173.3(4) pm] .…”

“…Both the molybdenum atoms of the central Mo 2 unit are surrounded by two amide nitrogen and two thioether sulfur atoms in a roughly square planar arrangement (Figure ). A similar coordination mode was recently observed in the case of the nickel(II) complexes [Ni{R 2 Si(NC 6 H 4 ‐2‐SR') 2 }] . However, contrary to the nickelcomplexes the Mo atoms in compound 3 are markedly more displaced from the mean plane through N and S atoms of the ligand (Mo(1): 52.6 pm, Mo(2): 46.1 pm).…”

“…However, contrary to the nickelcomplexes the Mo atoms in compound 3 are markedly more displaced from the mean plane through N and S atoms of the ligand (Mo(1): 52.6 pm, Mo(2): 46.1 pm). In the Ni II complexes the nickel atoms are situated exactly in N 2 S 2 mean plane . Unlike the nickel complexes the S bound methyl groups are in cis orientation with respect to the N 2 S 2 coordination plane.…”

“…The presence of the intramolecularly coordinating thioether groups leads to a markedly improved thermal stability of the Cu I , Ag I , and Au I silylamides. In the case of analogous Ni II silylamides intramolecular coordination of the thioether groups is even more pronounced than in the coinage metal derivatives and square‐planar complexes of the type [Ni(R 2 Si(NC 6 H 4 ‐2‐SR') 2 ] (R = Me, Ph; R' = Me, Ph, S‐ t Bu) were observed . We now have tried to apply thioether functionalized silylamides for the preparation of molybdenum(II) compounds in order to study the structural influence of the side arm donor groups.…”

Syntheses and crystal structures of three [M(acac)2(TMEDA)] complexes (M = Mn, Fe and Zn)

“…The synthesis of [Zn(acac) 2 (TMEDA)] was reported recently in conjunction with the Ru derivative but without crystal structure determination (Halbach et al, 2012). Typically, [M(acac) 2 (TMEDA)] complexes are used as valuable starting materials for the preparation of organometallic and coordination compounds (Kaschube et al 1988;Nelkenbaum et al, 2005;Albrecht et al, 2019). Moreover, there is an increasing interest in [M(acac) 2 (TMEDA)] and related [M(hfa) 2 (TMEDA)] (hfa = 1,1,1,5,5,5-hexafluoropentane-2,4-dionate) complexes as precursor materials for CVD deposition of Co 3 O 4 (Pasko et al, 2004), Fe 2 O 3 (Barreca et al, 2012) and MnF 2 (Malandrino et al, 2012).…”