Trans‐philicity (trans‐influence/trans‐effect) ladders for square planar platinum(II) complexes constructed by ³⁵Cl NMR probe

Abstract

The unified term of trans‐philicity is proposed to cover the trans‐effect/trans‐influence concepts. NMR trans‐philicity ladders are built for a broad series of square planar trans‐Pt(NH3)2(Cl)L and trans‐Pt(CO)2(Cl)L complexes employing 35Cl NMR probe and quantified by calculation of NMR trans‐philicity indicators. The trans‐philicity is linearly correlated with the ligand electronic PL constant, a measure of the net donor power of the ligand. The nature of cis‐ligands does not affect trans‐philicity ladders but strongly affects trans‐philicity strength. Solvent has significant effect on the σcalcd 35Cl shielding constants, with the polar Dimethylformamide (DMF) solvent inducing downfield shifts relative to σcalcd 35Cl with nonpolar benzene solvent. Good correlations between σcalcd 35Cl shielding constants and the estimated R(Pt‐Cl) bond distances demonstrate the relation of trans‐philicity with trans‐influence and trans‐effect phenomena and put the grounds for the establishment of the new concept of trans‐philicity in the realm of square planar Pt(II) and other transition metal complexes. © 2019 Wiley Periodicals, Inc.

NMR probe effects on trans-philicity and trans-influence ladders in square planar Pt(ii) complexes

“…These electronic effects have previously been quantified by well-established ligand electronic parameters, such as the P L constants defined as P L = E 1/2 [Cr(CO) 6 ] À E 1/2 [Cr(CO) 5 L]. [11][12][13] In a following paper 14 we applied the trans-philicity concept in the realm of square planar Pt(II) complexes where both transinfluence and trans-effects have frequently been epitomized and probe whether and to what extent the cis ligands affect trans philicity. Having in mind that trans-effect/trans-influence phenomena operate mutually along a linear L-M-X framework we report herein on the effect of the leaving group X (used as a NMR probe) on the trans-philicity and trans-influence ladders for a broad series of square planar trans-[Pt(PMe 3 ) 2 (X)L] n (n = 0, 1, 2; X = H, CO, CH 3 , NH 2 , OH 2 , Cl) complexes involving a wide variety of L (44 ligands) with diverse electronic features (s-donor, s-donor/p-donor, s-donor/p-acceptor ligands).…”

Building Blocks for Molecular Polygons Based on Platinum Vertices and Polyynediyl Edges

“… 11 − 14 , 29 , 30 The platinum–phosphorus bonds in the dichloride complex 2a (2.2290(8) and 2.2320(8) Å, Figure 8 ) are significantly shorter than those in the cis PtC≡C species (2.2923(9) to 2.3096(14) Å, Table 2 ), consistent with the greater trans effect of alkynyl ligands. 31 As can be seen in Figure S1 , some of the chelates exhibit chair-like conformations (e.g., 3b ), others half-chair (e.g., 3a ; see also Figure 6 ), and others different motifs ( 2a , 5a ) with little analogy in cyclohexane rings ( 2a , 5a ). These are presumably primarily determined by packing forces.…”