Preparation of potentially porous, chiral organometallic materials through spontaneous resolution of pincer palladium conformers.

نویسندگان

  • Magnus T Johnson
  • Zoran Džolić
  • Mario Cetina
  • Manu Lahtinen
  • Mårten S G Ahlquist
  • Kari Rissanen
  • Lars Öhrström
  • Ola F Wendt
چکیده

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 primarily form hexagonal crystals with large 1D channels, whereas the iodide (presumably due to its inferior hydrogen bonding capacity) forms monoclinic crystals without channels. The hexagonal channels are completely hydrophobic and filled with disordered solvent molecules. Upon heating, loss of the solvent occurs and the hexagonal crystals transform into other non-porous polymorphs. Also by introducing a strong acid, the crystallisation process can be directed to a different course, giving several different non-porous polymorphs. In conclusion, a number of rules can be formulated dictating the formation of hexagonal channel structures based on pincer palladium complexes. Such rules are important for a rational design of future self-assembling materials with applications in storage and molecular recognition.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Preparation of potentially porous , chiral organometallic materials through spontaneous resolution of pincer palladium conformers † Magnus

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 hydr...

متن کامل

Employment of Palladium Pincer Complex Catalysts and Lewis Acids for Synthesis and Transformation of Organometallic Compounds

This thesis is mainly focused on the development of new palladium catalyzed transformations using so-called “pincer” complexes. These complexes were applied as catalysts in two important areas of organometallic chemistry: substitution of propargylic substrates by dimetallic reagents; and allylation of aldehydes and imines by allylstannanes. In addition, this thesis includes studies on Lewis aci...

متن کامل

Enantioselective aza-Morita-Baylis-Hillman reactions of acrylonitrile catalyzed by palladium(II) pincer complexes having C2-symmetric chiral bis(imidazoline) ligands.

Significance: This paper describes the palladiumcatalyzed enantioselective aza-Morita–Baylis–Hillman reaction of acrylonitriles with imines. The bulky pincer ligand enabled the synthesis of enantioenriched α-methylene-β-aminonitriles in high yield. Comment: The palladium–pincer complex preferably activates acrylonitrile, even in the presence of ethyl acrylate. The palladium ketenimide is a key ...

متن کامل

A novel amphiphilic pincer palladium complex: design, preparation and self-assembling behavior.

Amphiphilic pincer palladium complexes bearing hydrophilic and hydrophobic side chains on the planar NCN palladium pincer backbone were designed and prepared via the ligand introduction route. The complexes self-assembled under aqueous conditions to form vesicles with bilayer membranes containing palladium species. The catalytic activity of the vesicles in the Miyaura-Michael reaction in water ...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Dalton transactions

دوره 42 23  شماره 

صفحات  -

تاریخ انتشار 2013