Concurrent and reversible changes of color and of phase in an aqueous solution of the (2,6-pyridinedicarboxylato)chloroplatinate(II) complex. Spectroscopic and crystallographic studies of the discrete monomer and evidence of a stacked polymer

Journal Article · Tue Nov 29 23:00:00 EST 1988 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00297a015· OSTI ID:5776251

Zhou, X; Kostic, N M

The title complex, (Pt(dipic)Cl)/sup /minus//, was prepared in a reaction between dipicolinate salts and (PtCl/sub 4/)/sup 2/minus//. The variation in temperature or in concentration of its aqueous solution causes two changes - of color and of phase - which are sudden concurrent, and reversible. At higher temperatures or lower concentrations the complex is yellow and monomeric, whereas at lower temperatures or attempted higher concentrations it is red and probably polymeric. The red form is microcrystalline and probably composed of stacked (Pt(dipic)Cl)/sup /minus// units. Unlike other square-planar complexes that form stacks, the yellow from of (Pt(dipic)Cl)/sup /minus// remains monomeric over a wide range of concentration and temperature until the sudden onset of the supposed polymerization. The nucleation and growth of the red from are easily monitored owing to the concomitant color change. The crystal structure for the monomeric salt is reported. The uv-vis spectrum of the red K(Pt(dipic)Cl) in the solid state contains a low-energy absorption band diagnostic of the stacking. This band disappears when the red polymer dissolves in water to give a yellow monomeric solution. The (Pt(dipic)Cl)/sup /minus// salts, like thermochromic materials, hold promise as temperature indicators. 62 refs., 4 figs., 5 tabs.

• Research Organization: Iowa State Univ., Ames (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5776251
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 27:24; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
AZINES
CARBOXYLIC ACID SALTS
CHLORIDES
CHLORINE COMPOUNDS
COMPLEXES
CRYSTAL STRUCTURE
DATA
EXPERIMENTAL DATA
HALIDES
HALOGEN COMPOUNDS
HETEROCYCLIC COMPOUNDS
INFORMATION
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PLATINUM COMPLEXES
POLYMERS
PYRIDINES
TRANSITION ELEMENT COMPLEXES