Table 1. Assignment of the Key Species Identified during the Course of the Time-Resolved ESI-MS Measurementsa.
| anion | m/z (obs) | z | assignment | m/z (calcd) |
|---|---|---|---|---|
| {SiW9} | 1128.6 | 2– | {NaH7[SiW9O34]} | 1128.7 |
| 1148.7 | 2– | {Na2H6[SiW9O34]·H2O} | 1148.7 | |
| 1156.6 | 2– | {KNaH6[SiW9O34]·H2O} | 1156.7 | |
| 1158.6 | 2– | {KNa2H5[SiW9O34]} | 1158.7 | |
| 1167.6 | 2– | {KNa2H5[SiW9O34]·H2O} | 1167.7 | |
| 1175.6 | 2– | {K2NaH5[SiW9O34]·H2O} | 1175.7 | |
| {β-SiW10} | 1244.6 | 2– | {NaH7[SiW10O37]} | 1244.7 |
| 1254.1 | 2– | {NaH7[SiW10O37]·H2O} | 1253.7 | |
| 1264.6 | 2– | {Na2H6[SiW10O37]·H2O} | 1264.7 | |
| 1273.1 | 2– | {KNaH6[SiW10O37]·H2O} | 1272.7 | |
| 1283.5 | 2– | {KNa2H5[SiW10O37]·H2O} | 1283.6 | |
| 1291.5 | 2– | {K2NaH5[SiW10O37]·H2O} | 1291.6 | |
| {γ-SiW10} | 1319.5 | 2– | {K5H[SiW10O36]} | 1319.6 |
| 1330.5 | 2– | {K5Na[SiW10O36]} | 1330.6 | |
| 1338.5 | 2– | {K6[SiW10O36]} | 1338.5 | |
| {β-SiW11} | 1399.5 | 2– | {KNa2H3[SiW11O39]·2H2O} | 1399.6 |
| 1408.5 | 2– | {K3NaH2[SiW11O39]} | 1408.6 | |
| 1419.5 | 2– | {K3Na2H[SiW11O39]} | 1419.6 | |
| 1427.5 | 2– | {K4NaH[SiW11O39]} | 1427.5 |
a
Both calculated and observed m/z values refer to the most intense, or monoisotopic, peaks in the isotopic envelope.