51-39-8Relevant academic research and scientific papers
The effect of chlorine and fluorine substitutions on tuning the ionization potential of benzoate-bridged paddlewheel diruthenium(II, II) complexes
Kosaka, Wataru,Itoh, Masahisa,Miyasaka, Hitoshi
, p. 8156 - 8168 (2015/05/13)
A series of paddlewheel diruthenium(II, II) complexes with various chlorine-substituted benzoate ligands (Cl-series) was synthesized as tetrahydrofuran (THF) adducts [Ru2(ClxPhCO2)4(THF)2]; where ClxPhCO2- = o-chlorobenzoate, o-Cl; m-chlorobenzoate, m-Cl; p-chlorobenzoate, p-Cl; 2,3-dichlorobenzoate, 2,3-Cl2; 2,4-dichlorobenzoate, 2,4-Cl2; 2,5-dichlorobenzoate, 2,5-Cl2; 2,6-dichlorobenzoate, 2,6-Cl2; 3,4-dichlorobenzoate, 3,4-Cl2; 3,5-dichlorobenzoate, 3,5-Cl2; 2,3,4-trichlorobenzoate, 2,3,4-Cl3; 2,3,5-trichlorobenzoate, 2,3,5-Cl3; 2,4,5-trichlorobenzoate, 2,4,5-Cl3; 3,4,5-trichlorobenzoate, 3,4,5-Cl3; 2,3,4,5-tetrachlorobenzoate, 2,3,4,5-Cl4. This Cl-series and the previously synthesized F-series together with four new fluorine-substituted derivatives, [Ru2(FxPhCO2)4(THF)2] (where FxPhCO2- = 2,3-difluorobenzoate, 2,3-F2; 2,4-difluorobenzoate, 2,4-F2; 2,5-difluorobenzoate, 2,5-F2; 2,3,5-trifluorobenzoate, 2,3,5-F3), were experimentally characterized with respect to solid-state structure, magnetic properties and electrochemistry. By tuning the substituents of the benzoate ligands using chlorine or fluorine atoms, the redox potential (E1/2) for [Ru2II,II]/[Ru2II,III]+ varied over a wide range of potentials from -40 mV to 360 mV (vs. Ag/Ag+ in THF). This was dependent on (i) the number of ortho-substituents, i.e. non-, mono- and di-o-substituted groups, with quasi-Hammett parameters for ortho-Cl and -F substitutions (σo = -0.272 and -0.217, respectively) and (ii) the general Hammett constants, σm and σp, for each group. The HOMO energy level calculated on the basis of the atomic coordinates of the solid-state structure was strongly affected by Cl- and F-substitutions as well as the redox potential in solution, which emphasizes the steric contribution of ortho-substituents in the energy level giving a deviation of EHOMO 0.3 eV and 0.55 eV for the Cl- and F-series, respectively.
Method for estimating SN1 rate constants: Solvolytic reactivity of benzoates
Matic, Mirela,Denegri, Bernard,Kronja, Olga
supporting information, p. 8986 - 8998,13 (2012/12/12)
Nucleofugalities of pentafluorobenzoate (PFB) and 2,4,6-trifluorobenzoate (TFB) leaving groups have been derived from the solvolysis rate constants of X,Y-substituted benzhydryl PFBs and TFBs measured in a series of aqueous solvents, by applying the LFER equation: log k = sf(Ef + Nf). The heterolysis rate constants of dianisylmethyl PFB and TFB, and those determined for 10 more dianisylmethyl benzoates in aqueous ethanol, constitute a set of reference benzoates whose experimental ΔG ? have been correlated with the ΔH? (calculated by PCM quantum-chemical method) of the model epoxy ring formation. Because of the excellent correlation (r = 0.997), the method for calculating the nucleofugalities of substituted benzoate LGs have been established, ultimately providing a method for determination of the SN1 reactivity for any benzoate in a given solvent. Using the ΔG? vs ΔH? correlation, and taking sf based on similarity, the nucleofugality parameters for about 70 benzoates have been determined in 90%, 80%, and 70% aqueous ethanol. The calculated intrinsic barriers for substituted benzoate leaving groups show that substrates producing more stabilized LGs proceed over lower intrinsic barriers. Substituents on the phenyl ring affect the solvolysis rate of benzhydryl benzoates by both field and inductive effects.
Proton mobility in 2-substituted 1,3-dichlorobenzenes: "ortho" or "meta" metalation?
Schlosser, Manfred,Heiss, Christophe,Marzi, Elena,Scopelliti, Rosario
, p. 4398 - 4404 (2007/10/03)
Nine 1,3-dichlorobenzene congeners were selected as model compounds to assess the relative rates of proton abstraction from 4- and 5-positions ("ortho" vs. "meta" metalation). Using lithium 2,2,6,6-tetramethylpiperidide as the basic reagent, the chlorine-adjacent 4-position underwent metalation exclusively. In contrast, attack at the chlorine-remote 5-posi" tion became significant even in the case of moderately sized 2-substituents (such as dimethylamino or ethyl) when secbutyllithium was employed. The "ortho/para" (4-/5-) ratios ranged from 80:20 to 65:35. The more pronounced "meta-orienting" effect of silicon as opposed to carbon substituents can be attributed to dissimilarities in the n polarization of the aromatic ring. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
Pharmacologically active CNS compound
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, (2008/06/13)
The invention provides a series of compounds of formula (I) and salts thereof, wherein for example,R1 and R2, which may be the same or different each represent -NR13R14 where R13 and R14 may each independently represent hydrogen or alkyl or, taken together with the nitrogen atom to which they are attached form a heterocyclic ring, optionally substituted by one or more alkyl or arylalkyl groups and optionally containing a further heteroatom;, R3 is hydrogen, haloalkyl, alkoxymethyl or alkyl;, R4 is hydrogen, nitro or halo;, R5 is hydrogen or halo;, R6 is hydrogen, halo, nitro, amino, alkylamino or dialkylamino;, R7 is hydrogen or halo;, R8 is hydrogen or halo; The compounds may be used for the treatment or prophylaxis of a neurodegenerative or other neurological disorder of the CNS, the aetiology or which includes excessive release of the neurotransmitter glutamate.
Pesticidal compounds
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, (2008/06/13)
Bicyclooctane pesticides of the formula are prepared by cyclisation of In these formulae R may be various organic groups and is preferably n-butyl or n-propyl while R2 is a polysubstituted phenyl group.
