Table 1.
Rates of reaction of varied carbonyl compounds with phenyllydrazine in aqueous buffer at pH 7.4.a
| Substrate | k1(obs) (min−1) | k2(app) (M−1sec−1) | krel | Substrate | k1(obs) (min−1) | k2(app) (M−1sec−1) | krel | ||
|---|---|---|---|---|---|---|---|---|---|
| Aryl aldehydes | |||||||||
| 1 |
|
0.0020 (0.0005) | 0.033 (0.008) | 1 | 11 |
|
0.20 (0.06) | 3.4 (1.0) | 100 |
| 2 |
|
0.009 (0.004) | 0.15 (0.06) | 4.5 | 12 |
|
0.076 (0.032) | 1.3 (0.6) | 39 |
| 3 |
|
0.007 (0.002) | 0.12 (0.03) | 3.6 | 13 |
|
0.030 (0.002) | 0.50 (0.03) | 15 |
| 4 |
|
0.009 (0.004) | 0.15 (0.07) | 4.5 | 14 |
|
0.026 (0.002) | 0.43 (0.03) | 13 |
| 5 |
|
0.009 (0.002) | 0.15 (0.04) | 4.3 | Ketones | ||||
| 6 |
|
0.005 (0.003) | 0.09 (0.04) | 2.8 | 15 |
|
0.013 (0.004) | 0.22 (0.07) | 6.7 |
| 7 |
|
0.013 (0.008) | 0.22 (0.13) | 6.7 | 16 |
|
0.017 (0.006) | 0.28 (0.10) | 8.6 |
| 8 |
|
0.008 (0.001) | 0.13 (0.02) | 3.9 | 17 |
|
0.034 (0.002) | 0.57 (0.03) | 17 |
| 9 |
|
0.006 (0.002) | 0.10 (0.03) | 3.0 | 18 |
|
0.046 (0.006) | 0.77 (0.10) | 23 |
| Alkyl aldehydes | 19 |
|
0.022 (0.010) | 0.37 (0.17) | 11 | ||||
| 10 |
|
0.58 (0.14) | 9.7 (2.3) | 290 | |||||
a
Conditions: 137 mM NaCl, 2.7 mM KCl, 10 mM phosphate, 25 °C. Values measured 3–6 times and averaged (std. dev. in parentheses). Pseudo-first-order k(obs) normalized to standard 1000 μM aldehyde concentration.