Simple and easy functionalization of -hydroxy POCOP-M (M = Ni(II), Pd(II)) pincer complexes: synthesis of multimetallic species.

A facile and efficient method for synthesizing mono- and bi-metallic pincer complexes (3-Ni/Ni and 3-Ni/Pd) has been developed. The procedure involves a 1 : 1 stoichiometric reaction of a -hydroxy POCOP pincer complex with cyanuric chloride in the presence of [NaB(OMe)], which selectively affords the mono-substituted pincer complexes (2-Ni and 2-Pd). These complexes are then further reacted with another equivalent of the -hydroxy POCOP pincer complex to produce the desired multimetallic species (3-Ni/Ni and 3-Ni/Pd).

Fluorinated-NHC Transition Metal Complexes: Leading Characters as Potential Anticancer Metallodrugs.

In the last 20 years, N-Heterocyclic Carbene (NHC) ligands have been ubiquitous in biological and medicinal chemistry. Part of their success lies in the tremendous number of topologies that can be synthesized and thus finely tuned that have been described so far. This is particularly true in the case of those derivatives, including fluorine or fluorinated fragments on their NHC moieties, gaining much attention due to their enhanced biological properties and turning them into excellent candidates for the development of novel metallodrugs.

Synthesis, biological evaluation and model membrane studies on metal complexes containing aromatic N,O-chelate ligands.

Novel lanthanide (Ln) compounds [Ln(L)]ClxHO (Ln = La, Ce, Sm) containing aromatic N,O-chelate ligands [HL1 = 4-amino-2-(1-benzimidazol-2-yl)phenol; HL2 = 5-amino-2-(1-benzimidazol-2-yl)phenol] have been synthesized and structurally characterized by elemental analysis, NMR and IR spectroscopy, molar conductance measurements, and mass spectrometry (MS). The spectroscopic data suggested that the benzimidazolyl-phenol ligands act as N,O-chelate ligands through the iminic nitrogen and phenolic oxygen atoms. Elemental analysis indicated that lanthanide compounds were formed in a 1:2 stoichiometry (metal:ligand).

Bi- and tridentate stannylphosphines and their coordination to low-valent platinum.

Semirigid bifunctional tin-substituted o-tolylphosphines of general formulae [PhP(o-CHCH)SnR] (R = Ph, 1; R = Me, 2) and [{PhP(o-CHCH)}SnPh] (3) were synthesized and isolated in good yields. The new compounds were fully characterized by single-crystal X-ray diffraction and multinuclear solution NMR spectroscopic techniques. The observed J(Sn,P) values in solution NMR spectroscopy as well as the PSn distances in the solid state and DFT calculations (B3LYP) on compounds 1 and 3 do not support the existence of intramolecular P → Sn bond interactions in either of the three compounds.

Lithium Complexes Derived of Benzylphosphines: Synthesis, Characterization and Evaluation in the ROP of rac-Lactide and ε-Caprolactone.

A series of lithium complexes ([Ph₂P(-C₆H₄-CH₂Li·TMEDA)] (), [PhP(-C₆H₄-CH₃)(-C₆H₄-CH₂Li·TMEDA)] (), [PhP(-C₆H₄-CH₂Li·TMEDA)₂] () and [P(-C₆H₄-CH₂Li·TMEDA)₃] ()) was prepared from mono-, di- and tri-benzylphosphines and varying amounts of BuLi and was characterized extensively by IR and ¹H, ⁷Li, C and P NMR spectroscopy. The molecular structures of complexes and were determined by single-crystal X-ray diffraction studies. The two complexes have monomeric structures in the solid state comprising seesaw lithium atoms.

A family of rhodium and iridium complexes with semirigid benzylsilyl phosphines: from bidentate to tetradentate coordination modes.

The synthesis of a new trisbenzylsilanephosphine P{(o-CHCH)SiMeH} (1) is shown to proceed with high yields from P(o-tolyl). Compound 1 coordinates to the Rh and Ir dimers [MCl(COD)] (M = Rh, Ir) in a tetradentate or tridentate fashion, depending on the strict exclusion of water. The dimeric compounds [ClM(SiMeCH-o-CH)P(o-CH-CHSiMeH)], 2Rh and 2Ir, feature a tetradentate coordination of the starting ligand with P and two Si atoms as well as a non-classical agostic Si-H group.

Do planar tetracoordinate tin complexes really exist?

New experimental and theoretical data show that the previously reported planar tetracoordinate Sn complexes [Sn(Ph₂P(Se)N(Se)PPh₂)₂] (1-sq) and [Sn(iPr₂P(Se)N(Se)PiPr₂)₂] (2-sq) were not isolated and rather confused with the selenium complexes [Se(Ph₂P(Se)N(Se)PPh₂)₂] (3-sq) and [Se(iPr₂P(Se)N(Se)PiPr₂)₂] (4-sq), respectively.

Calix[4]arenes of aluminum and gallium with benzimidazolyl ligands: steric control of the conformation via substitution on the ligand.

Complexes [bzimAlR(2)](4) [bzim = benzimidazolate; R = Et (2), (i)Bu (3)], [mbzimAlR(2)](4) [mbzim = 2-methylbenzimidazolate; R = Et (6), (i)Bu (7)], [dmbzimAlR(2)](4) [dmbzim = 5,6-dimethylbenzimidazolate; R = Me (9), Et (10), (i)Bu (11)], and [tmbzimAlR(2)](4) [tmbzim = 2,5,6-trimethylbenzimidazolate; R = Me (12), Et (13), (i)Bu (14)] have been prepared via alkane elimination and coordinative self-assembly upon the reaction of benzimidazole ligands with aluminum alkyls in benzene, toluene, or xylene. Characterization of the complexes was achieved by spectroscopic methods, microanalysis, and X-ray crystallography of 2, 7, 10, 11, 13, and 14. The complexes reported herein and the aluminum and gallium analogues 1, 4, 5, and 8 reported in a previous paper (1) are predominantly tetranuclear aggregates related to calix[4]arenes in which the benzimidazolyl ligands bind two metal atoms in a η(1):η(1) fashion.

Steric control of conformation in self-assembly metallacalix[4]arenes derived from AlMe3 or GaMe3 with benzimidazolyl ligands.

Metallacalix[4]arenes [bzimAlMe(2)](4) (1), [bzimGaMe(2)](4) (2), [mbzimAlMe(2)](4) (3) and [mbzimGaMe(2)](4) (4) were obtained by self-assembly. The larger cavity of 3 and 4 allows them to function as hosts of benzene molecules.