Formation and homolysis of a mononuclear cobalt-oxygen adduct

Journal Article · Wed Mar 14 04:00:00 EST 1990 · Journal of the American Chemical Society; (USA)

DOI:https://doi.org/10.1021/ja00162a030· OSTI ID:6518617

Bakac, A; Espenson, J H ^[1]

---

1. Iowa State Univ., Ames (USA)

The macrocyclic cobalt(II) complex (H{sub 2}O){sub n}Co(C-meso-Me{sub 6}(14)aneN{sub 4}){sup 2+} (L{sup 2}Co{sup 2+}) binds oxygen to yield L{sup 2}CoO{sub 2}{sup 2+}. The rate constants for the binding and release of O{sub 2} in aqueous solution at 25{degree}C have values 5.0 {times} 10{sup 6} M{sup {minus}1} s{sup {minus}1} and 1.66 {times} 10{sup 4} s{sup {minus}1}, respectively. There is no evidence for the formation of a binuclear {mu}-peroxo complex. The ESR parameters of the oxygen adduct in toluene at 120 K, g{sub {parallel}} = 2.108, g{sub {perpendicular}} = 3.81 {times} 10{sup {minus}3} cm{sup {minus}1}, A{sub {perpendicular}} = 2.94 {times} 10{sup {minus}3} cm{sup {minus}1}, are consistent with the formulation of the complex as a 1:1 adduct with the unpaired spin density residing on the oxygen. The laser flash photolysis of L{sup 2}CoO{sub 2}{sup 2+} ({lambda}{sub irr} 490 nm) induces the cleavage of the cobalt-oxygen bond, L{sup 2}CoO{sub 2}{sup 2+} {yields}{sup hv} L{sup 2}Co{sup 2+} + O{sub 2}.

• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 6518617
• Journal Information: Journal of the American Chemical Society; (USA), Journal Name: Journal of the American Chemical Society; (USA) Vol. 112:6; ISSN 0002-7863; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ADDUCTS
BONDING
COBALT COMPLEXES
COMPLEXES
DATA
DATA ANALYSIS
EXPERIMENTAL DATA
FABRICATION
INFORMATION
JOINING
KINETICS
MEASURING INSTRUMENTS
MEASURING METHODS
NUMERICAL DATA
OXYGEN COMPLEXES
REACTION KINETICS
TRANSITION ELEMENT COMPLEXES