1H-pyrazolo［5,1-C] [1,2,4] triazole (hereinafter referred to as "pyrazolo-triazole")
Pyrazolo-triazole is a coupler.
Due to the variations of the substituent on the 4 equivalent pyrazolo-triazolic structure of mother nucleus,
there exist hight energy level of the coupler's HOMO(H) and low one(L), even within the appropriate range.
Due to the introduction of halogen atom into the carbon atom on the active point of those couplers,
the energy level of coupler's (Next)HOMO decrease.
(When a halogen atom is introduced into the carbon at the coupler's active point,
it is necessary to concider not only the energy level of HOMO but also the energy level of NextHOMO.)
In the case of (H), the energy level of halogenized 2-equivalent coupler's (Next)HOMO remains within an appropriate range and its coupler shows sufficient coupling reactivity.
In the case of (L), the energy level of halogenized 2-equivalent coupler's (Next)HOMO goes down over an appropriate range and its coupler shows unsufficient coupling reactivity.
When the cyan dye produced from pyrazolotriazole(H) is compared to the cyan dye produced from pyrazolotriazole(L),
on the triazole side the cyan dye becomes a shortened wave and appears as a shoulder of the absorption waveform.
(See "The first reaction kinetics in the world with regard to indoaniline dye forming (6)")
phenolic coupler and 2-carbamoylnaphtholic coupler
Even when the conventional 4-equivalent phenolic coupler is (H) and the 4-equivalent 2-carbamoylnaphtholic coupler is (L), the same phenomenon has occured.
Both (H) and (L) show sufficient coupling reactivity.
The halogenized 2-equivalent couple(H) shows sufficient coupling reactivity.
The halogenized 2-equivalent couple(L) shows unsufficient coupling reactivity.
Therefor, the phenomenon can be explained based on the same logic described in this blog.
azomethine dye forming reaction
In the case of azomethine dye forming reaction,
the relationship between a 4-equivalent coupler and 2-equivalent coupler in the coupling reaction's rate,
the relationship between a 4-equivalent coupler and 2-equivalent coupler in the dye forming reaction's rate,
and the relationship between the coupling reaction's rate and the dye forming rate also can be explained based on the logic described in this blog.
HOMO : Highest Occupied Molecular Orbital
LUMO : Lowest Unoccupied Molecular Orbital
conclusion
All the facts described in this blog post are well known or publicly known but the reaction kinetics itself which is as the title of this blog post.
References: The following publications are references for further details.
The Theory of the Photographic Process FOURTH EDITION Edited by T.H.James MACMILLAN PUBLISHING CO., INC.
Molecular Orbital Method Written by Minoru Hirota SHOKABO Co., Ltd.
Frontier Orbitals and Organic Chemical Reactions Written by Ian Fleming Supervised by Kennichi Fukui Translated by Takeuchi Yoshito, Tomoda Syuuji KODANSHA SCIENTIFIC Co., Ltd.
The Seminar of Organic Chemical Reactions Witten by Naoki Inamoto,Kinya Akiba,Renji Okazaki NANKODO Co., Ltd.
Physical Chemistry Written by Raymond Chang Translated by Iwasawa Yasuhiro, Kitagawa Teizou, Hamaguchi Hiroo TOKYOKAGAKUDOJIN Co., Ltd.
KONICA MINORUTA TECHNOLOGY REPORT VOL2 (2005)
https://research.konicaminolta.com/jp/pdf/technology_report/2005/pdf/treatise_014.pdf
Klopman/ Salem Equation
http://ramsey1.chem.uic.edu/chem533/page5/page10/files/Klopman-Salem%20Equation.pdf
