*From*: Adam Tenderholt <atenderholt-,-gmail.com>*Subject*: CCL: HOMO energy and redox potential*Date*: Thu, 01 Sep 2016 14:17:44 +0000

Hi Muhammad, Unless there is some underlying physical reason that allows one to derive the the relationship you proposed, I think it's just a mathematical fit. If you change the exponent on r, from say 2 to 6, you'll still get "reasonable" linear fits for IP ~ log(-k). For example, here's r^3: > k3 = V/(m*(r^3)) > pro <- lm(IP ~ log(-k3)) > summary(pro) Call: lm(formula = IP ~ log(-k3)) Residuals: 1 2 3 4 5 -11.023 27.474 -15.087 2.521 -3.885 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) -1892.162 377.784 -5.009 0.01532 * log(-k3) 32.791 5.304 6.182 0.00852 ** --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 19.37 on 3 degrees of freedom Multiple R-squared: 0.9272, Adjusted R-squared: 0.903 F-statistic: 38.22 on 1 and 3 DF, p-value: 0.008523 Best, Adam On Mon, Aug 29, 2016 at 10:24 AM Muhammad Abduh Nasution abduh^ mhs.unimed.ac.id <owner-chemistry(~)ccl.net> wrote: > > Sent to CCL by: "Muhammad Abduh Nasution" [abduh]~[mhs.unimed.ac.id] > Dear CCL members. > First, forgive me if this > discussion may be not too > computational chemistry. I've > read many literature states that > there are relationship between > HOMO energy and redox > potential, even this topic can be > found on CCL archive. So I try to > relate them based on data from > "Oxtoby, D. W. (2008). > Principles of Modern > Chemistry" and "Lide, David R. > (ed). (2005). CRC Handbook of > Chemistry and Physics". I found > that Ionization Potential of > alkali metal and logaritmic > function from \frac{V}{Mr\times > r^5}\ (where V is redox potential > in Volt, Mr is relative mass of > atom in kg, and r is atomic radii > in m), is have strong correlation > showed by its R-squared. Here > is script written in R, altough > basically I'm python > programmer. > # data sequences of alkali > metal properties > > element<- > c('Li','Na','K','Rb','Cs') > # Ionization Potential of alkali > metal > > IP<- > c(520.2,495.8,418.8,403,375.7) > # redox potential of alkali metal > > V<- c(-3.0401, -2.71, -2.931, - > 2.98, -3.026) > # defining Angstrom unit > > A = 10^-10 > # atomic radii of alkali metal > > r<- c(1.52*A, 1.86*A, 2.27*A, > 2.47*A, 2.65*A) > # atomic relative mass of alkali > metal in kg > > m<- c(0.0069412, > 0.02298977, 0.03909831, > 0.08546783, 0.132905452) > # defining k > > k = V/(m*(r^5)) > # relating between k and > ionization potential > > data <- data.frame(x=log(-k), > y=IP) > > pro <- lm(y ~ x, data=data) > > summary(pro) > Call: lm(formula = y ~ x, data = > data) Residuals: 1 2 3 4 5 - > 10.883 25.245 -13.378 2.646 - > 3.629 Coefficients: Estimate > Std. Error t value Pr(>|t|) > (Intercept) -14167.3 2164.1 - > 6.547 0.00725 ** x 3074.9 > 455.5 6.751 0.00664 ** --- > Signif. codes: 0 '***' 0.001 '**' > 0.01 '*' 0.05 '.' 0.1 ' ' 1 Residual > standard error: 17.84 on 3 > degrees of freedom Multiple R- > Squared: 0.9382, Adjusted R- > squared: 0.9177 F-statistic: > 45.58 on 1 and 3 DF, p-value: > 0.006638 > > data.entry(data) > > plot(data) > > Well, is it relationship right? or it > is just mathematical fit? If it is > right, what theory behind it? I've > search for it but until now I not > get the theory. > Best Regards > > Muhammad Abduh > > > > -= This is automatically added to each message by the mailing script =-> > >