Synthesis and Study of Hexanuclear Molybdenum Clusters Containing Thiolate Ligands

Abstract

Four hexanuclear molybdenum chloride cluster complexes containing terminal thiolate ligands have been synthesized and fully characterized. (Bu 4N) 2[Mo 6Cl 8(SEt) 6] was prepared by reacting Na 2[Mo 6Cl 8(OMe) 6] with an excess of ethanethiol in refluxing tetrahydrofuran. (PPN) 2[Mo 6Cl 8(SBu) 6], (Bu 4N) 2[Mo 6Cl 8(SBn) 6], and (Bu 4N) 2[Mo 6Cl 8(SNC 8H 6) 6] (C 8H 6NS (-) = 3-indolylthiolate) were subsequently prepared in the reaction of [Mo 6Cl 8(SEt) 6] (2-) with an excess of HSR (R = Bu, Bn or 3-indolyl). Single crystal X-ray diffraction analyses were performed on two of these complexes: (PPN) 2[Mo 6Cl 8(SEt) 6].Et 2O, crystallizes in the triclinic space group P1 with a = 12.3894(11), b = 13.7651(12), c = 15.0974(13), alpha = 103.975(2), beta = 99.690(2), gamma = 98.062(2), and Z = 1; (PPh 3Me) 2[Mo 6Cl 8(SBn) 6].2NO 2CH 3, also crystallizes in the P1 space group with a = 12.1574(16), b = 13.4441(17), c = 14.2132(18), alpha = 89.654(2), beta = 88.365(2), gamma = 71.179(2), and Z = 1. Our studies demonstrate that [Mo 6Cl 8(SEt) 6] (2-) displays luminescent properties and that the same complex undergoes substitution reactions with different thiols, as well as reaction with electrophilic reagents such as MeI.

Long-chain alkyl thiols in Langmuir monolayers

“…Cations belonging to the 12th group of the periodic table are special in the aspect that they have completely occupied the d orbitals, which usually leads to the formation of binary, linear complexes of these metals with alkyl thiols. Other transition metals also form strong complexes with thiol molecules present at the water/air interface; however, on the basis of their capability of complex formation with different transition metals it can be inferred that the coordination number in the observed complexes can be larger than 2 [36].…”

Triblock copolymer-based luminescent organic–inorganic hybrids triggered by heating and fluoroquinolone antibiotics

“…We have reported [21] enhanced water solubility of [K(diglyme)(CH 3 [22,25]. Steady state luminescence intensity (I) and excited state lifetime (τ) values tend to decrease on going from L64-to P123-based solutions of 1 [21].…”

“…It is worth noting that literature data highlight, first of all, the change of inner-and outer-sphere environment as a powerful tool to tune Mo-centered luminescence by an apical ligands substitution [14][15][16] and counter-ions exchange [19,21]. However, the applicability of apical ligands substitution methodology is restricted by low lability of the apical positions, which makes ligand exchange procedures rather time and energy consuming [22,23]. Fortunately, outer-sphere environment of the cluster anions is another significant factor affecting their luminescence.…”

Synthesis, crystal structure, and photophysical properties of acid (H3O)2[{W6Br8}Br6] · 4H2O

“…Tens of works presenting the luminescence proper ties of various octahedral molybdenum and rhenium clusters have been published to date [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. However, the photophysical properties of the W 6 clusters are poorly studied.…”

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It is well known that upon UV irradiation many chalcogenide and halide hexanuclear clusters of tran sition metals, for example, [{Re 6 Q 8 }L 6 ] (Q = S, Se) and [{M 6 X 8 }L 6 ] (M = Mo, W; X = Cl, Br), where L are various inorganic and organic ligands, luminesce in the red spectral range with microsecond emission life times [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Phosphorescence in the red spectral range and, as a consequence, the ability to generate singlet oxygen, as well as specific features of the struc tures of similar octahedral clusters of heavy metals, suggest that these compounds are potentially promis ing for the use as photosensitizers in photodynamic therapy and as X ray contrast preparations in diagnos tics of oncological diseases.

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