Electronic Absorption Spectra and Phosphorescence of Oxygen-Containing Molybdenum(IV) Complexes
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- 作者：Ralph A. Isovitsch ; A. Scott Beadle ; Frank R. Fronczek ; and Andrew W. Maverick
- 刊名：Inorganic Chemistry
- 出版年：1998
- 出版时间：August 24, 1998
- 年：1998
- 卷：37
- 期：17
- 页码：4258 - 4264
- 全文大小：103K
- 年卷期：v.37,no.17(August 24, 1998)
- ISSN：1520-510X
文摘
Electronic absorption and emission spectra are reported for salts of two oxomolybdenum(IV) cations, [MoOCl(CN-t-Bu)4]+ and [MoOCl(Ph2PCH2CH2PPh2)2]+, and for the new Mo(IV) complex [trans-Mo(OCH3)2(CN-t-Bu)4]2+. All three ions show absorption bands (
max,abs 550-570 nm; 
45-120 M-1 cm-1) attributable to the1A1[(dxy)2] 
1E[(dxy)1(dxz,yz)1] (C4v) transition, and the last two show weak shoulders in the 700-750 nm rangedue to the analogous spin-forbidden (1A1 3E) transition. Phosphorescence (max,em 850-960 nm) occurs in thesolid state for all three compounds at both room temperature and 77 K, and for [MoOCl(CN-t-Bu)4]+ in CH2Cl2at room temperature. These are the first phosphorescences recorded for molybdenum(IV) complexes. [MoOCl(CN-t-Bu)4](BPh4) precipitates quickly if NaBPh4 is added to the Mo(IV) solution prepared from MoCl5 andtert-butyl isocyanide in CH3OH. However, if NaPF6 is used instead, [trans-Mo(OCH3)2(CN-t-Bu)4](PF6)2 (formedby reaction of [MoOCl(CN-t-Bu)4]+ with methanol) crystallizes over a period of ca. 24 h. The crystal structureof [trans-Mo(OCH3)2(CN-t-Bu)4](PF6)2 has been determined: C22H42F12MoN4O2P2, monoclinic; space group P21/c; a = 9.1538(8) Å, b = 15.709(2) Å, c = 13.456(2) Å; 
= 103.31(1)
; Z = 2; R(F) = 0.063, Rw(F) = 0.056for 2719 reflections with I > 
(I).
max,abs 550-570 nm; 45-120 M-1 cm-1) attributable to the1A1[(dxy)2] 1E[(dxy)1(dxz,yz)1] (C4v) transition, and the last two show weak shoulders in the 700-750 nm rangedue to the analogous spin-forbidden (1A1 3E) transition. Phosphorescence (max,em 850-960 nm) occurs in thesolid state for all three compounds at both room temperature and 77 K, and for [MoOCl(CN-t-Bu)4]+ in CH2Cl2at room temperature. These are the first phosphorescences recorded for molybdenum(IV) complexes. [MoOCl(CN-t-Bu)4](BPh4) precipitates quickly if NaBPh4 is added to the Mo(IV) solution prepared from MoCl5 andtert-butyl isocyanide in CH3OH. However, if NaPF6 is used instead, [trans-Mo(OCH3)2(CN-t-Bu)4](PF6)2 (formedby reaction of [MoOCl(CN-t-Bu)4]+ with methanol) crystallizes over a period of ca. 24 h. The crystal structureof [trans-Mo(OCH3)2(CN-t-Bu)4](PF6)2 has been determined: C22H42F12MoN4O2P2, monoclinic; space group P21/c; a = 9.1538(8) Å, b = 15.709(2) Å, c = 13.456(2) Å; = 103.31(1); Z = 2; R(F) = 0.063, Rw(F) = 0.056for 2719 reflections with I > (I).