The preparation of halogenotrimolybdate(II) compounds

Abstract

The preparation of halogenotrimolybdate(II) compounds containing the staphylonuclear groups, (Mo3Cl13)7-, (Mo3Br13)7-, (Mo3Cl12)6-,(Mo3Cl11)5-, (Mo3Br11)5-, (Mo3Br11)5- has been thoroughly examined and 11 new compounds are reported. No iodomolybdate(II) compounds were observed. When (NH4)7Mo3Cl13,H2O is heated in vacuum, ammonium chloride is evolved but the final product is never MoCl2. This chloromolybdate(II) undergoes rapid reaction with refluxing acetic acid to give an approximately two-thirds yield of molybdenum(II) acetate. This suggests the cleaving of an Mo3 group to give Mo2(CH3CO2)4. Crystalline [Co en3]3Mo3Cl15,6H2O undergoes spontaneous intramolecular redox reaction which is stimulated by light, or moisture, but not oxygen.

Stoichiometric and structural characterization of the compound (NH4)5Mo2Cl9.H2O

“…In fact, the actual differences in analytical (±) are mean deviations from the average, where these are large enough to make the esd meaningless. 6 Owing to disorder in this case, the quoted esd's are triple those actually calculated in the hope of not seriously underestimating the true uncertainties. percentages are so small as to make the two formulas indistinguishable in practice.…”

“…Figure 2a shows the arrangement in the 0, y, z plane. Interleaving the mirror planes, there are crinkled sheets made up of the rest of the ammonium (5) Mo(l)-Cl(l) 2.486 (9) Mo(l)-Cl(2) 2.467 (7) Mo(l )-Cl(3) 2.415(13) Mo(2)-Cl(4) 2.490 (10) Mo(2)-Cl (5) 2.487 (7) Mo(2)-Cl (6) 2.483 (16) Mean 2.47 ± 0.02 with a mean value of 90.0°" Numbers in parentheses are estimated standard deviations occurring in the last significant figure. Numbers following the ± sign are mean deviations from the mean.…”

“…The standard deviation of an observation of unit weight was 2.7, indicating a slight underestimation of error in the data. An empirical -?t¡ 3) 9 (2) 35 (2) 6 (2)…”

Preparation of some compounds containing multiple molybdenum-molybdenum bonds

“…are mean deviations from the average, where these are large enough to make the esd meaningless. 6 Owing to disorder in this case, the quoted esd's are triple those actually calculated in the hope of not seriously underestimating the true uncertainties.…”

“…Constant-boiling hydrochloric acid (CBHC1) was prepared by evaporating reagent grade concentrated hydrochloric acid (12 M, 37 wt %) at its boiling point and allowing it to cool while prepurified nitrogen was bubbled through it. It is approximately 6 M, contains about 20.2 wt % of HC1, and has a boiling point of 108°( 760 Torr).…”