Guanidinates as chelating anionic ligands for early, middle and late transition metals: syntheses and crystal structures of [Ti{η2-(NPh)2CNEt2}2Cl2], [Ru{η2-(NPh)2CNHPh}3] and [Pt{η2-(NPh)2CNHPh}2]

Crystal structure of dichloro{[anilino(phenylimino)methyl]- (propanimidoyl)azanide}-[η2-(N,N′-diphenylguanidinato)]platinum(IV) – deuterochloroform (1:1), PtCl2(C13H12N3)(C16H17N4) · CDCl3

“…PtN(H)=C(Et)NC(N(H)Ph)=NPh [1,2]. The N5-C23 and N6-C23 bond lengths (1.352(2) and 1.327(2) Å,respectively) within the four-membered chelate ring formed by h 2 -diphenylguanidinato ligand are similar (within 3s)tothose found in related CN bonds in the (NPh) 2C-N(H)2 h 2 -N,N'-diphenylguanidinato ligand in the Mo complex [5], and (NPh) 2C-NHPh h 2 -N,N',N''-triphenylguanidinato ligand in the Pt, Pd, Ru and Mo complexes [5][6][7][8], as well as to the CN bonds found in the h 2 -(NPh) 2CNEt2 ligand in some Ti complexes [6]. Such bond lengths are consistent with the presence of ad elocalized NCN ligand backbone.…”

A Highly Efficient Titanium Catalyst for the Synthesis of Ultrahigh‐Molecular‐Weight Polyethylene (UHMWPE)

“…The N‐C‐N angle between the ligating nitrogen atoms is considerably smaller than 120° (106–110°), whereas the remaining angles are greater than 120° (124–128°). However, the sum of the angles around the central carbon atom in each chelating guanidinate ligand is 360° indicating no deviation from planarity 13. Complex 5 shows the same bond length of 1.353(4) Å for all three CN bonds; they are therefore indistinguishable, indicating considerable delocalization of the uncoordinated nitrogen atom lone pair into the ligand π system 14.…”

Stabilisation of high oxidation-state niobium using ‘electron-rich’ bicyclic-guanidinates

“…Previous work by ourselves and others have shown that the [hpp] À anion chelates to a range of different main group and transition metals [2], including lithium [3], aluminium [4], tin [5], zinc [6], yttrium [7] and titanium [8,9]. Crystallographic data for a series of mono-and bis-ligand compounds of titanium has indicated notably shorter Ti-N distances in [Ti(hpp)Cl 2 (l-Cl)] 2 and Ti(hpp) 2 Cl 2 when compared to the corresponding benzamidinate [10] and acyclic guanidinate [11] compounds. These data are commensurate with an increased donation of p-electron density to the d 0 -titanium centre, although it is noted that the reduced steric influence of the bicyclic framework may also play a role in the close ligand-metal interactions.…”