Synthesis of Various Cationic Ruthenium−Aqua Complexes with Hydrotris(3,5-diisopropylpyrazolyl)borate Ligand, Tp^iPrRu(OH₂)_n(L)_3-n·(CF₃SO₃)(THF)_x, and Their Structures Supported by Hydrogen-Bonding Networks¹

The labile cationic aqua complex, Tp^iPrRu(OH₂)₂(THF)·(OTf)(THF)₂, 2, containing the hydrotris(3,5-diisopropylpyrazolyl)borate ligand (Tp^iPr), is prepared by protonolysis of the ruthenium pentahydride complex Tp^iPrRuH₅, 1, with trifluoromethanesulfonic acid (TfOH) in THF. Treatment of 2 with various 2e and 4e donors results in displacement of the THF and aqua ligands to give Tp^iPrRu(OH₂)_n(L)_3-n·(OTf)(THF)_x, 3−6 (L= py, bipy, phen, pz^iPr-H, PPh₃, dppe, MeCN, ^tBuCN, CC(H)Ph; n = 0−2), and thus, complex 2 serves as a versatile precursor for a variety of cationic ruthenium aqua complexes. X-ray crystallographic analysis of the di- (2, 3b,c) and monoaqua complexes (4c, 5) reveals ternary hydrogen-bonding networks among the aqua, OTf^-, and THF fragments.