Search results for "Pincer movement"
showing 6 items of 16 documents
Molecular “Pincer” from a Diimidazolium Salt: A Study of Binding Ability
2013
The anion recognition ability of the dicationic imidazolium salt 3,3′-di-n-octyl-1,1′- (1,3-phenylenedimethylene)diimidazolium 1,5-naphthalenedisulfonate ([m-Xyl-(oim)2][1,5-NDS]) was investigated in acetonitrile solution by means of proton NMR titrations. A wide range of anions, comprising simple inorganic ions, halides, and mono- and dicarboxylates was taken into account. The study showed that this receptor binds carboxylate anions more strongly than halides. Moreover [m- Xyl-(oim)2][1,5-NDS] displays selectivity for di- over monocarboxylate anions. The complex stability was mainly affected by the anion basicity in the presence of monocarboxylates, whereas the flexibility of the alkyl cha…
Osmium(III) Complexes with POP Pincer Ligands: Preparation from Commercially Available OsCl3·3H2O and Their X-ray Structures
2010
Complexes OsCl3{dbf(PiPr2)2} [1; dbf(PiPr2)2 = 4,6-bis(diisopropylphosphino)dibenzofuran], OsCl3{xant(PiPr2)2} [2; xant(PiPr2)2 = 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene], and OsCl3{xant(PPh2)2} [3; xant(PPh2)2 = 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene] have been obtained in high yield by the reaction of the corresponding diphosphine with OsCl3·3H2O. The ruthenium(III) counterparts RuCl3{dbf(PiPr2)2} (4), RuCl3{xant(PiPr2)2} (5), and RuCl3{xant(PPh2)2} (6) are similarly obtained from RuCl3·3H2O in moderate yields. The X-ray structures of dbf(PiPr2)2 and complexes 1−3 are also reported.
Optically Active Hyperbranched Polyglycerol as Scaffold for Covalent and Noncovalent Immobilization of Platinum(II) NCN-Pincer Complexes. Catalytic A…
2004
New optically active hyperbranched polymers have been used as microenvironments as well as scaffolds for noncovalent and covalent immobilization of pincer platinum(II) complexes, respectively. The catalytic activity/selectivity of the incorporated platinum(II) complexes in these polymeric chiral supports was investigated. Chiral amphiphilic hyperbranched polyglycerols with core−shell “nanocapsules” structure, namely (−)-P(G40C160.5) (1) and (+)-P(G73C160.5) (2), have been prepared in two straightforward steps by ring-opening multibranching polymerization (ROMBP) of either (−)- or (+)-glycidol, resulting in (−)-PG40 (Mn = 3000, Mw/Mn = 1.3) or (+)-PG73 (Mn = 5500, Mw/Mn = 1.6), respectively.…
Cyclotriveratrylene-Containing Porphyrins
2016
International audience; The C-3-symmetric cyclotriveratrylene (CTV) was covalently bonded via click chemistry to 1, 2, 3, and 6 zinc(II) porphyrin units to various host for C-60. The binding constants, Ka, were measured from the quenching of the porphyrin fluorescence by C-60. These constants vary between 400 and 4000 M-1 and are considered weak. Computer modeling demonstrated that the zinc(II) porphyrin units, [Zn], exhibit a strong tendency to occupy the CTV cavity, hence blocking the access for C-60 to land on this site. Instead, the pincer of the type [Zn]-[Zn] and in one case [Zn]-CTV, were found to be the most probable geometry to promote host-guest associations in these systems.
{Bis[2-(diisopropylphosphanyl)ethyl]amine}carbonyl(tetrahydroborato)cobalt(I)
2018
In the structure of title borohydride pincer complex, [Co(BH4)(C16H37NP2)(CO)], the cobalt(I) metal exhibits a distorted square-pyramidal coordination geometry with the basal positions occupied by the P and N atoms of the tridentate ligand and by the C atom of the carbon monoxide ligand. In the crystal, molecules interact only by van der Waals forces.
Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers.
2013
Understanding the mechanism by which advanced materials assemble is essential for the design of new materials with desired properties. Here, we report a method to form chiral, potentially porous materials through spontaneous resolution of conformers of a PCP pincer palladium complex ({2,6-bis[(di-t-butylphosphino)methyl]phenyl}palladium(II)halide). The crystallisation is controlled by weak hydrogen bonding giving rise to chiral qtz-nets and channel structures, as shown by 16 such crystal structures for X = Cl and Br with various solvents like pentane and bromobutane. The fourth ligand (in addition to the pincer ligand) on palladium plays a crucial role; the chloride and the bromide primaril…