The Synthesis, Structure, and FTIR Spectroelectrochemistry of W(CO)₅ Complexes of 4‐Oxo‐4‐(2,5‐dimethylazaferrocen‐1′‐yl)butanoic and 5‐Oxo‐5‐(2,5‐dimethylazaferrocen‐1′‐yl)pentanoic Acids

Abstract

With the aim of developing new IR-detectable metal-carbonyl tracers for the amino function, we have synthesized W(CO) 5 complexes of 4-oxo-4-(2,5-dimethylazaferrocen-1Ј-yl)butanoic acid (2) and 5-oxo-5-(2,5-dimethylazaferrocen-1Ј-yl)pentanoic acid (3) by AlCl 3 -catalyzed Friedel-Crafts reaction of W(CO) 5 -2,5-dimethylazaferrocene (1) with succinic or glutaric anhydride. Complexes 2 and 3 are thermally stable and display sharp, intense absorption bands of tungsten-coordinated CO ligands at ca. 1923 cm -1 . In the crystalline state, molecules of 2 and 3 are stabilized by a network of intra-and intermolecular hydrogen bonds, as shown by single-crystal X-ray structure analysis. Complex 2 was transformed into the corresponding N-succinimidyl ester 4. Its utility toward labeling of amino acids was tested in its reaction with glycine methyl ester. Corresponding glycine amide

The synthesis, structure, electrochemistry and in vitro anticancer activity studies of ferrocenyl-thymine conjugates

“…This (11) 1.473 (5) 1.468(6) C(11)eC (12) 1.516 (5) 1.491(6) C(11)eO (1) 1.223(4) 1.221(5) C(12)eC (13) 1.500 (5) 1.309(7) C(13)eC(l1) 1.781(4) e C(2)eN(1)eC (5) 106.5(3) 106.1(3) W(1)eN(1)eC (2) 68.8(2) 68.9(2) W(1)eN(1)eC (5) 69.5(2) 69.4(2) O(1)eC(11)eC (10) 121.0(3) 120.4(4) O(1)eC(11)eC (12) 121.6(3) 120.7(4) C(10)eC(11)eC (12) 117.3 (3) 118.9(4) C(11)eC(12)eC (13) 114.6(3) 122.6(4) C(11)eC(13)eC (12) 112.8(3) e C(10)eC(11)eC(12)eC (13) 173.9(5) 179.8(4) O(1)eC(11)eC(12)eC (13) À5.4(5) À0.4 (7) reflects a weak but still measurable electron-withdrawing effect of the thymine end-chain group. The observed voltammetric profiles of W(CO) 5 -2,5-dimethylazaferrocenes 12a and 12b closely resemble ones reported by us previously for other W(CO) 5 -2,5-dimethylazaferrocenes derivatives [50]. In anodic scans, cyclic voltammograms of 12a and 12b shows two waves.…”

“…Pertinent data are collected in Table 4 along with electrochemical data for known W(CO) 5 -2,5-dimethylazaferrocene 12 [50], 3-chloropropionylferrocene 11a and acryloylferrocene 11b as a comparison. Figs.…”

Spectroscopic, Structural and DFT Study of the Responses of Carbonylmetal Crown Ether Complexes to Alkali Metal Cations

“…It can be seen that there is considerable variation in the positions of the symmetric and antisymmetric bands. The expectation is that binding a metal cation in the crown influences charge distribution in the complex in much the same way as has been observed11 for hydrogen bonding at pyrazine ligands in Cr(CO) 5 complexes, for dissociation of carboxylic acid substituents on ligands in Fe(CO) 3 and Cr(CO) 3 complexes,12 and in an electrochemical investigation13 of W(CO) 5 (azaferrocene) adducts with potential applications as IR‐detectable tracers for amino groups. In previous studies14 we have found that Bellamy plots15 are a convenient method to depict results of this type.…”