Synthesis and photochemical properties of zirconium phosphonate-viologen compounds as porous solids and transparent thin films

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:141081

Thompson, M E; Vermeulen, L; Snover, J ^[1]

---

1. Princeton Univ., NJ (United States)

The authors have recently reported the photochemical properties of crystalline layered zirconium phosphonate viologen compounds (Zr(O{sub 3}PCH{sub 2}CH{sub 2}(bipyridyl)CH{sub 2}CH{sub 2}PO{sub 3})X{sub 2}; ZrPV (X); x = halide). Photolysis of these white compounds with solar or high intensity ultraviolet light results in the formation of a blue solid, which remains blue for several hours in the air and indefinitely under argon. The blue color is due to reduced viologen, which is half of a very long-lived charge separated state. In order for the photochemically reduced viologen to be accessible for reaction with suitable substrates, the authors have prepared related compounds, which are porous. Porosity can be achieved by synthesizing mixed phosphonates [i.e. Zr(PV(X)){sub 1{minus}x}(O{sub 3}PR){sub 2x}], in which R is H or OH. In these mixed materials the viologens act as pillars to hold the zirconium phosphonate lamellae apart, making the resultant material porous. The synthesis, structures and photochemical properties of mixed phosphonates will be described. The materials as synthesized are microcrystalline powders. To eliminate the light scattering problems associated with these materials they have been prepared as thin films, supported on glass. The synthesis and photochemical properties of these films will be described.

• OSTI ID: 141081
• Report Number(s): CONF-930304--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
BIPYRIDINES
CHEMICAL PREPARATION
PHOSPHONATES
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
POROUS MATERIALS
THIN FILMS
ZIRCONIUM COMPOUNDS