Preparation and crystal structures of complexes of uranium(4+) methyltrihydroborate(1-) with 1,2-dimethoxyethane, N,N,N',N'-tetramethylethylenediamine, and 1,2-bis(methylthio)ethane

Abstract

Complexes of U(BH3CH3)4 with CH3OCH2CH2OCH3, (CH3)2NCH2CH2N(CH3)2, and CH3SCH2CH2SCH3 have been synthesized and their molecular structures determined by single-crystal X-ray diffraction. U(BH3CH3)4-CH3OCH2CH2OCH3 is tetragonal, P4/n, with a = 21.822 (8) Á, c = 7.681 (5) Á, Z = 8, d = 1.61 g/cm3, and R = 0.028 [F2 > 'ia{F2)]\ U(BH3C-H3)4-(CH3)2NCH2CH2N(CH3)2 is monoclinic, P2t/n, with a = 10.206 (4) k,b= 15.436 (6) A, c = 12.880 (5) A, ß = 92.25 (3) °, Z = 4,d = 1.54 g/cm3, and R = 0.029 (F2 > 3 ( 2)); U(BH3CH3)4-CH3SCH2CH2SCH3 is triclinic, PI, with a = 8.937 (4) k,b= 13.692 (4) A, c = 8.186 (3) k, a = 96.46 (4)°, ß = 97.64 (4)°, = 74.07 (4)°, Z = 2, d = 1.66 g/cm3, and R = 0.023 (F2 > 2a(F2)). With one exception, all BH3CH3 groups are coordinated to the uranium atoms by tridentate hydrogen bridges with a U-B bond distance of 2.55 ± 0.02 A. For the (CH3)2NCH2CH2N(CH3)2 complex one B atom is coordinated to the uranium atom through a bidentate hydrogen bridge with a U-B distance of 2.72 (2) A and a U-B-C angle of 142 (2)°.

Uranium(IV) Thio‐ and Selenoether Complexes: Syntheses, Structures, and Computational Investigation of U−ER2Interactions

“…In the structure of 5, the acridanide backbones of the AS 2 3) Å. These distances are within the sum of the covalent radii for sulfur and uranium (3.01 Å), [18] and are shorter than those in most uranium(IV) thioether complexes {3.089(1) Å in [Cp*U{k 6 -B 3 (Cat) 6 }(SMe 2 )], [19] 3.04(1) and 3.09(1) Å in [(k 2 -MeSCH 2 CH 2 SMe)U(BH 3 Me) 4 ], [20] and 3.120(4)-3.275(4) Å in [{(MeBH 3 ) 4 U(μ-THT)} 2 ]}. [21] However, shorter UÀ S distances {2.763(2), 2.779(2) Å} were previously observed in [(k 3 -TXA 2 )UCl 3 ] À {TXA 2 = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tertbutyl-9,9-dimethylthioxanthene} in which the thioether is incorporated into the backbone of a rigid dianionic NSN-donor ligand.…”

Early Transition Metal Complexes of Polydentate and Macrocyclic Thio- and Seleno-Ethers

“…Dark green [U(BH 3 Me) 4 (MeSCH 2 CH 2 SMe)] can be described as either 14-coordinate U, or if the tridentate H 3 BMe groups are conceptually treated as monatomic ligands, distorted octahedral. 10 Competitive NMR experiments show that the affinity of the U(BH 3 Me) 4 fragment for neutral ligands increases MeOCH 2 CH 2 OMe < MeSCH 2 CH 2 SMe < Me 2 NCH 2 CH 2 NMe 2 < Me 2 PCH 2 CH 2 PMe 2 . 10…”

“…8) is the expected fac octahedron with relatively long Cr-S bonds (2.396(av) trans Cl, 2.500(1) Å trans N). Chromium(III) complexes of acyclic bi-and poly-dentates include 33,34 35 There are a number of thiacrown complexes, mostly of type [CrX 3 (L)] (X = Cl, sometimes Br; L = [9]aneS 3 , [10] 37 The best route is reaction of [CrX 3 (thf) 3 ] with the thiacrown in a non-coordinating solvent, the volatile thf is easily removed under reduced pressure. In some cases CrX 3 .6H 2 O has been used, 38 but this route fails to give isolable products with many thiacrowns, and a starting material containing a hard strong donor (H 2 O) is a poor choice when synthesising soft donor complexes of a hard metal centre.…”

Rigid NON- and NSN-ligand complexes of tetravalent and trivalent uranium: comparison of U–OAr2 and U–SAr2 bonding

“…Only a small number of actinide complexes containing soft neutral chalcogen donors 11 have been reported. Crystallographically characterized non-uranyl examples include [Cp*An IV {κ 6 -B 3 (Cat) 6 }(SMe 2 )] (An = Th, U; Cat = ortho-O 2 C 6 H 4 ], 12 [(κ 2 -MeSCH 2 CH 2 SMe)U IV (BH 3 Me) 4 ], 13 [{(MeBH 3 ) 4 U IV (μ-THT)} 2 ] (THT = tetrahydrothiophene), 14 [(C 5 R 5 ) 3 U III (THT)], 15 [(κ 3 -9S3) An III I 3 (NCMe) 2 ] (An = U or Pu; 9S3 = 1,4,7-trithiacyclononane = 9-thiacrown-3), 16,17 and [(κ 6 -18S6)U III (BH 4 ) 2 ][BPh 4 ] (18S6 = 18-thiacrown-6), 18 and [{κ 3 -HRB(mim) 2 } 2 U III (THF) 3 ][BPh 4 ] (R = H or Ph; mim = N-methylthioimazolyl); 19…”