Synthesis of a Uranyl Persulfide Complex and Quantum Chemical Studies of Formation and Topologies of Hypothetical Uranyl Persulfide Cage Clusters

Abstract

The compound Na(4)[(UO(2))(S(2))(3)](CH(3)OH)(8) was synthesized at room temperature in an oxygen-free environment. It contains a rare example of the [(UO(2))(S(2))(3)](4-) complex in which a uranyl ion is coordinated by three bidentate persulfide groups. We examined the possible linkage of these units to form nanoscale cage clusters analogous to those formed from uranyl peroxide polyhedra. Quantum chemical calculations at the density functional and multiconfigurational wave function levels show that the uranyl-persulfide-uranyl, U-(S(2))-U, dihedral angles of model clusters are bent due to partial covalent interactions. We propose that this bent interaction will favor assembly of uranyl ions through persulfide bridges into curved structures, potentially similar to the family of nanoscale cage clusters built from uranyl peroxide polyhedra. However, the U-(S(2))-U dihedral angles predicted for several model structures may be too tight for them to self-assemble into cage clusters with fullerene topologies in the absence of other uranyl-ion bridges that adopt a flatter configuration. Assembly of species such as [(UO(2))(S(2))(SH)(4)](4-) or [(UO(2))(S(2))(C(2)O(4))(4)](4-) into fullerene topologies with ~60 vertices may be favored by use of large counterions.

Reactivity of uranium(iv) bridged chalcogenido complexes UIV–E–UIV(E = S, Se) with elemental sulfur and selenium: synthesis of polychalcogenido-bridged uranium complexes

“…In 2). These bond distances are at the shorter end of known S-S bond lengths observed in other uranium 1,19,50,[57][58][59][60][61] and transition metal complexes, [62][63][64][65][66] featuring the persuldo ligand S 2 2À . However, the very rare supersuldo complexes of the transition metals have shown a wider range for the S-S bond length, ranging from 1.944-2.023 Å, depending on the metal center, the supporting ligand, and the coordination mode.…”

“…(Table 2). These bond distances are at the shorter end of known S-S bond lengths observed in other uranium 1,19,50,[57][58][59][60][61] and transition metal complexes, [62][63][64][65][66] featuring the persuldo ligand S 2…”

Synthesis of Terminal Uranium(IV) Disulfido and Diselenido Compounds by Activation of Elemental Sulfur and Selenium

“…28 The US distances of 2.628(2) and 2.6214(19) Å are the same within error, and within the range of U IV thiolates (2.588 to 2.736 Å), supporting anionic interactions between sulfur and uranium 10. 29, 30 The US bonds in 2 are also similar to U VI terminal disulfido compounds,31–33 including [( n ‐C 3 H 7 ) 2 NH 2 ] 2 [(UO 2 )(( n ‐C 3 H 7 ) 2 NCOS) 2 (η 2 ‐S 2 )], which has distances of 2.711(3) and 2.873(2) Å, and the uranyl persulfido, Na 4 [(UO 2 )(η 2 ‐S 2 ) 3 (CH 3 OH) 8 ,34 with distances ranging from 2.751(1) to 2.796(1) Å. The SS bond of 2.075(3) Å in 2 is within error of that reported for [( n ‐C 3 H 7 ) 2 NH 2 ] 2 [(UO 2 )(( n ‐C 3 H 7 ) 2 NCOS) 2 (η 2 ‐S 2 )] (2.05(1) Å) and similar to those for Na 4 [(UO 2 )(η 2 ‐S 2 ) 3 ](CH 3 OH) 8 (2.077(2) to 2.082(2) Å) as well as other terminal disulfido complexes for uranium (2.077(2) to 2.09(1) Å)31–33 and transition metals (2.010 to 2.072 Å),35–39 supporting the formation of the S 2 2− moiety.…”

“…], which has distances of 2.711(3) and 2.873(2) , and the uranyl persulfido, Na 4 [34] with distances ranging from 2.751(1) to 2.796 (1) . The S À S bond of 2.075(3) in 2 is within error of that reported for [(n- (1) ) and similar to those for Na 4 8 (2.077(2) to 2.082(2) ) as well as other terminal disulfido complexes for uranium (2.077(2) to 2.09(1) ) [31][32][33] and transition metals (2.010 to 2.072 ), [35][36][37][38][39] supporting the formation of the S 2 2À moiety.…”

Two-electron versus one-electron reduction of chalcogens by uranium(iii): synthesis of a terminal U(v) persulfide complex

“…This complex presents a terminal h 2 -S 2 2À group which is extremely rare in uranium chemistry and only found in few uranyl(VI) complexes [39][40][41] and provides the rst example of the two-electron oxidation of U(III) by elemental sulfur. Diuranium(IV) chalcogenide-bridged complexes were also prepared from the reactions of complex 1 with chalcogens (Scheme 1).…”