Spectroscopic and structural studies on 1 : 2 adducts of silver(I) salts with tricyclohexylphosphine

Abstract

A series of monomeric [AgX(P(C,H, complexes have been prepared for X = CN, I, Br, C1, SCN, NCO, NO, or CIO, and characterized by single-crystal X-ray determinations, solid-state cross polarization magic angle spinning (CP MAS) ,'P NMR, solution 31P NMR and far-infrared spectroscopy. For X = CN, I, Br, C1 or SCN the crystal structures are isomorphous, crystallizing in a monoclinic C2jc cell with a z 17, b = 9.3, c' z 25 A. p z 1 lo", 2 = 4; the SCN complex exhibits anion disorder/space group ambiguity. For X = NCO or NO, (redetermined) the structures are isomorphous with the previously studied perchlorate, crystallizing in a triclinic P I cell derivative of the C2jc array with a z 9.3, b e 9.8, c = 23 A, CX z 95, p = 96, y z 116". The Ag-P bond lengths correlate inversely with the P-Ag-P angles and depend on the donor properties of the anion X, with, however, a reverse trend noted for the halide complexes. The solid-state CP MAS ,'P NMR spectra show splitting due to 'J(P-Ag) coupling which progressively increases from 322 Hz for X = CN to 505 Hz for X = C10,. For the triclinic species further splitting is observed and assigned to 'J(P-P) coupling between the crystallographically inequivalent phosphorus atoms. These NMR results are consistent with the structural results except for the chloride and perchlorate systems where experiments suggest that both triclinic and monoclinic phases co-crystallize in proportions which depend on the recrystallization procedures. Solution 'lP NMR spectra show doublets assignable to 1 : 2 species. For X = Br, C1, NCO or SCN signals assignable to 1 : 1 species are also observed. Comparison with solid-state data show differences in 'J(P-Ag) that are ascribed to differences in B(P-Ag-P) in the solution and solid states. Far-IR spectra of the halide and pseudo-halide complexes in the series exhibit single bands due to v(AgX) vibrational modes at 207, 149, 121 for X = C1, Br or I and at 288, 241 and 174 cm-' for X = CN, NCO or SCN, these latter results providing rare data for the vibrational frequencies of terminal Ag-C, Ag-N and Ag--S bonds.

Concomitant polymorphic behavior of di-μ-thiocyanato-κ2 N:S;κ2 S:N-bis[bis(tri-p-fluorophenylphosphine-κP)silver(I)]

“…The traces of both polymorphs showed large endotherms at 386.75 and 402.90 K. The energies related to these two endotherms are relatively high compared with the heats of fusion for the two polymorphs. Dimeric structures [Ag 2 X 2 L 2 ] have previously been described as partially separated monomers (Bowmaker et al, 1996). We propose a similar behaviour for [Ag 2 (SCN) 2 {P(4-FC 6 H 4 ) 3 } 4 ] in the solid state.…”

Coordination Chemistry of the cyclo‐(P5tBu4)− Ion: Monomeric and Oligomeric Copper(I), Silver(I) and Gold(I) Complexes

“…Compound 1, [6] [CuClA C H T U N G T R E N N U N G (PCyp 3 ) 2 ], [11] [CuClA C H T U N G T R E N N U N G (PPh 3 ) 3 ], [23] [AgClA C H T U N G T R E N N U N G (PPh 3 ) 2 ], [24] and [AuClA C H T U N G T R E N N U N G (PPh 3 )] [25] were prepared according to the literature proce- Semi-empirical absorption corrections for 3, 7, 8 and 9 were carried out by using SADABS; [26] semi-empirical from equivalents absorption corrections for 4, 5 and 6 were carried out by using SCALE3 ABSPACK. [27] All the structures were solved through direct methods.…”

Coordination complexes of silver(I) with tertiary phosphine and related ligands

“…The complexes [AgX{P(4-MeC 6 H 4 ) 3 } 2 ], where X is halide or CN − , are thought to exist as monomers, with trigonal geometries [49] in solution, as was inferred by NMR spectroscopy. The complexes [AgX(PCy 3 ) 2 ] (X = Cl − , Br − , I − ) were structurally characterised as monomers [50]. Complexes with a L:Ag stoichiometry of 2:1, containing bulky phosphine ligands and non-coordinating anions, are thought to have linear two-coordinate structures.…”