Synthesis of copper(II) and nickel(II) triazacycloalkane complexes

Nonoyama, Matsuo

doi:10.1007/bf01385945

Cited by 20 publications

(3 citation statements)

References 16 publications

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“…This strategy was not successful, however, despite numerous attempts either to add nitrite salts to Tp RR‘ Cu I compounds or to reduce preformed Tp RR‘ Cu II −NO 2 - complexes. 17b,18b Reasoning that nitrite coordination to a Tp RR‘ Cu I fragment might be disfavored in the nonpolar solvents most amenable for the handling of hindered Tp RR‘ complexes because of charge considerations (Tp RR‘ is a monoanion, making the copper(I) fragment neutral and a derived nitrite adduct anionic), we turned to the sterically hindered, neutral macrocycles 1,4,7-triisopropyl-1,4,7-triazacyclononane (L i -Pr 3 ) and 1,4,7-tribenzyl-1,4,7-triazacyclononane (L Bn 3 ) recently reported by Wieghardt and co-workers. The trialkyl substituents borne by these molecules render them and their complexes soluble in many organic solvents and prevent deleterious bis(ligand) complex (L 2 Cu) formation, as seen with the unsubstituted 1,4,7-triazacyclononane few examples of copper(I) complexes of these ligands existed at the outset of our work …”

Section: Resultsmentioning

confidence: 93%

Synthetic Modeling of Nitrite Binding and Activation by Reduced Copper Proteins. Characterization of Copper(I)−Nitrite Complexes That Evolve Nitric Oxide

et al. 1996

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In an effort to provide precedence for postulated intermediates in copper-protein-mediated nitrite reduction, a series of novel complexes containing the Cu I -NO 2 -unit, including monocopper(I), dicopper(I,I), and mixed valence dicopper(I,II) and copper(I)-zinc(II) species, were prepared, fully characterized, and subjected to reactivity studies designed to probe their ability to produce nitric oxide. Treatment of solutions of [LCu(CH 3 CN)]PF 6 (L ) L i-Pr 3 , 1,4,7-triisopropyl-1,4,7-triazacyclononane, or L Bn 3 , 1,4,7-tribenzyl-1,4,7-triazacyclononane) in MeOH with excess NaNO 2 yielded the novel dicopper(I,I) complexes [(LCu) 2 (µ-NO 2 )]PF 6 . The complex with L ) L i-Pr 3 was cleaved by PPh 3 to afford [L i-Pr 3 Cu(PPh 3 )]PF 6 and L i-Pr 3 Cu(NO 2 ), a structural model for the substrate adduct of copper nitrite reductase. Oxidation of the dicopper(I,I) compound (L ) L i-Pr 3 ) with (Cp 2 Fe)(PF 6 ) in CH 2 Cl 2 yielded the deep red, mixed valent, dicopper(I,II) species [(L i-Pr 3 Cu) 2 (µ-NO 2 )](PF 6 ) 2 , which was structurally characterized as its [B(3,5-(CF 3 ) 2 C 6 H 3 ) 4 ] -salt (crystal data: triclinic space group P1 h, a ) 13.439(8) Å, b ) 13.777(5) Å, c ) 14.471(8) Å, R ) 108.22(4)°, β ) 92.08(5)°, γ ) 90.08(4)°, Z ) 1, T ) 177 K, R ) 0.074, and R w ) 0.070). A diamagnetic heterodinuclear Cu I Zn II analog, [L i-Pr 3 Cu(µ-NO 2 )ZnL i-Pr 3 ](O 3 SCF 3 ) 2 , was assembled by mixing L i-Pr 3 Cu(NO 2 ), Zn(O 3 -SCF 3 ) 2 , and L i-Pr 3 and was shown to adopt a structure similar to that of its Cu I Cu II relative (crystal data: monoclinic space group P2 1 /c, a ) 10.8752(1) Å, b ) 15.6121(3) Å, c ) 25.8020(5) Å, β ) 90.094(1)°, Z ) 4, R1 ) 0.0472, and wR2 ) 0.1082). Both compounds exhibit an intense electronic absorption feature that was assigned as a Cu I f NO 2 -MLCT transition on the basis of resonance Raman spectroscopic results.

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Section: Resultsmentioning

confidence: 93%

Synthetic Modeling of Nitrite Binding and Activation by Reduced Copper Proteins. Characterization of Copper(I)−Nitrite Complexes That Evolve Nitric Oxide

et al. 1996

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“…Two types of copper(II) complexes of cyclic triamines have been reported: (1) bis complexes which likely contain the CuN6 chromophore with tetragonally distorted octahedral stereochemistry6•7 and (2) dimeric species containing chloro and/or hydroxy bridges.7 The larger ring ligands apparently have a propensity toward the formation of the chloroand hydroxy-bridged dimers. 7 We have isolated a copper(II) complex of the [ll]aneN3, [Cu([11]aneN3)2] ( 03)2• 20, and we have studied its infrared and electronic spectra and magnetic susceptibility. The infrared spectrum indicates that nitrate is present as the free ion35 with bands observed at 825 (m, sp), 1370 (vs, br), and 707 cm"1 (w, sp).…”

Section: Discussionmentioning

confidence: 99%

Metal complexes of cyclic triamines. 2. Stability and electronic spectra of nickel(II), copper(II), and zinc(II) complexes containing nine- through twelve-membered cyclic triamine ligands

Zompa¹

1978

Inorg. Chem.

145

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Acknowledgment.We are indebted to the Science Research Council and the University of London Intercollegiate Research Service for financial support. We also thank Mr. J. R.Campbell for measuring the excitation profile of ARG and TSI. R m t r y NO. WR, 50600-57-2; RG, 58559-78-7; ARG, 12081-56-0; TSI, 60428-74-2. References and Notes(1) J. S. Miller and A. The acidity constants of three cyclic triamines, 1,4,7-triazacyclodecane ([ 10]aneN3), 1,4,8-triazacycloundecane ([ 1 l]aneN3), and 1,5,9-triazacyclododecane ([12]aneN3), were measured at 25 O C in aqueous 0.1 F KN03. The formation constants of each of these amines with Ni(II), Cu(II), and Zn(I1) were obtained as well as the hydrolysis equilibrium constants for several of the complexes. The results indicate that these complexes are generally more stable than those with the corresponding linear or branched triamine ligands. The stability of the cyclic triamines varies inversely with ligand ring size. The electronic spectra of Ni[x]aneN3*+ (x = 9, 10, 11, 12) are presented and trends in the ligand field parameter (04) and nephelauxetic ratio (@) for these complexes are discussed. The compounds [Ni[ 12]aneN,(OH)(H20)2]C10, and [Cu( [ 1 l]aneN&J-(N03)2.H20 were synthesized and isolated. Electronic and infrared spectra are presented along with magnetic susceptibility data.

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“…The series of cyclic triamines presents a nearly ideal system to study the properties of metal complexes which contain ligands with similar coordinative tendencies yet which progressively distort the stereochemical environment of the metal. Several investigations of metal complexes of cyclic triamines have appeared in the literature, − and the interest in these and similar cyclic compounds where one or more nitrogen atoms are replaced by other heteroatoms continued to grow. The extra stability of [9]aneN 3 complexes has been well documented, − and the work with the remaining congeners suggested that these cyclic amines behave similarly.…”

Section: Introductionmentioning

confidence: 99%

Reactions of Dichloroperfluorocycloalkenes with Triazamacrocyclic Amines

Gupta¹,

Chen²,

Kirchmeier³

et al. 1998

Inorg. Chem.

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1,2-Dichlorotetrafluorocyclobutene (A) and 1,2-dichlorohexafluorocylopentene-1 (B) were reacted with triazamacrocyclic amines (1,4,8-triazacycloundecane (1) and 1,5,9-triazacyclo-dodecane (2)) at 80 °C in the presence of stoichiometric amounts of triethylamine in benzene. Cycloalkene A formed a 2:1 product 3 with 1 and a 3:1 product 4 with 2. Cycloalkene B formed only 2:1 products 5 and 6 with 1 and 2, respectively. The crystal structures of 3 and 4 were determined by single-crystal X-ray diffraction.

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Synthesis of copper(II) and nickel(II) triazacycloalkane complexes

Abstract: SummaryCopper(ll) and nickel(ll) complexes of triazacycloalkanes

Cited by 20 publications

References 16 publications

Synthetic Modeling of Nitrite Binding and Activation by Reduced Copper Proteins. Characterization of Copper(I)−Nitrite Complexes That Evolve Nitric Oxide

Synthetic Modeling of Nitrite Binding and Activation by Reduced Copper Proteins. Characterization of Copper(I)−Nitrite Complexes That Evolve Nitric Oxide

Metal complexes of cyclic triamines. 2. Stability and electronic spectra of nickel(II), copper(II), and zinc(II) complexes containing nine- through twelve-membered cyclic triamine ligands

Reactions of Dichloroperfluorocycloalkenes with Triazamacrocyclic Amines

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