Tetraplatinum precursors for supramolecular assemblies: syntheses, crystal structures, and stereoselective self-assemblies of [Pt₄(μ-OCOCH₃)₆(κ⁴-N₄-DArBp)] (DArBp = 1,3-bis(arylbenzamidinate)propane)

Abstract

Treatment of the cisoid-capped complex [Pt(4)(micro-OCOCH(3))(6)(kappa(4)-N(4)-DAr'Bp)] (), which was obtained from the reaction of [Pt(4)(micro-OCOCH(3))(8)] (1) with Na(2)D(t)BuPhBp (D(t)BuPhBp = 1,3-bis(para-tert-butylphenylbenzamidinate)propane), with an equimolar amount of 1,1'-ferrocenedicarboxylic acid undergoes a stereoselective self-assembly to afford an indented-quadrangle tetramer [Pt(4)(micro-OCOCH(3))(4)(kappa(4)-N(4)-D(t)BuPhBp){Fe(C(5)H(4)COO)(2)}](4) as a single diastereomer.

Rational Synthesis of Supramolecular Assemblies Based on Tetraplatinum Units: Synthesis, Characterization, and Selective Substitution Reactions of Four Different Pt4 Clusters

“…The mean Pteq O distance (2.26 ) of the trans-positioned acetate is longer by 0.06 than that of cispositioned acetates (2.20 ) and by 0.1 than that of complex 1 (2.16 ), which indicates a unique trans influence through the Pt-Pt bond from the amidinate ligand, a tendency also observed in cis-capped complexes 9 and 10 (2.23 ). [30] The mean PtÀN bond length (2.17 ) of 8 d is comparable to that of 2 d (2.14 ).…”

“…[ 30] In sharp contrast to complexation in the mixed solvent of dichloromethane and methanol, reaction of 9 c and 1,1'-ferrocenedicarboxylic acid in a mixture of acetonitrile and methanol resulted in the formation of the cyclic dimer 17 as a main product together with 16 (Scheme 6). Once separately isolated by recrystallization, complexes 16 and 17 did not interconvert to each other in CDCl 3 .…”

“…Synthesis and characterization of cis-capped Pt 4 complexes 9: Although cis-capped Pt 4 complexes have been communicated elsewhere, [30] herein we highlight their synthesis and reactions. We designed a new chelating ligand suitable for coordinating in a cis manner to two adjacent sides of the planar Pt 4 square.…”

“…Figure 9 shows the cyclic dimer structure of 17, in which the rotation angle of two ferrocenyl linkers was 72.9 and 107.18, and thereby more acute than that found for tetramer 16 (125.6 and 115.98). [30] The two Pt 4 units are connected in a stair-step manner by two ferrocenyl linkers. Within each Pt 4 unit, bond lengths and angles are consistently normal and almost the same as those in 9 c (Table 3).…”

“…Part of this study concerning cis-capped bis(amidinate) Pt 4 complexes was communicated previously. [30] Results and Discussion Synthesis and characterization of bis(N,N'-diarylformamidinate) Pt 4 complexes 2 and mono(N,N'-diarylformamidinate) Pt 4 complexes 8: To rationally introduce a suitable nonlabile bridging ligand at the trans sides of the square-planar Pt 4 , N,N'-diarylformamidinate (ArNCHNAr) [17,22] was used as the N,N'-donor bridging ligands. The two amidinate ligands selectively occupy two in-plane coordination sites in a trans manner (Scheme 1a) due to the congestion of aryl moieties on the N atoms of the amidinate ligands, which prevent the occupation of adjacent side positions (Scheme 1b).…”