The kinetically favored triazole-based phosphine 1-(2-(diphenylphosphino)phenyl)-4-phenyl-1H-1,2,3-triazole (2, L1) and its thermodynamically preferred isomer, 5-(diphenylphosphino)-1,4-diphenyl-1H-1,2,3-triazole (3, L2), were obtained by the temperature-controlled lithiation of 2-bromotriazole followed by the reaction with chlorodiphenylphosphine. The structures of phosphines 2 and 3 were determined by X-ray diffraction. Upon reaction with late transition-metal derivatives (Cu(I), Ag(I), and Au(I)), phosphines 2 and 3 form complexes with monodentate (Cu(I), Ag(I), and Au(I); κ(1)-P), chelate (Cu(I); κ(2)-P,N), bridged bidentate (Cu(I); μ(2)-P,N), and tridentate (Cu(I); μ(2),κ(2)-P,N,N) modes of coordination. Reactions with copper(I) halides produced mono-, di-, and tetranuclear complexes, whereas the reaction of 2 with [Cu(NCCH3)4]BF4 yielded the binuclear complex [Cu2(CH3CN)2{o-Ph2P(C6H4){1,2,3-N3C(Ph)C(H)}-μ-(κ-P,κ-N),κ-N}2](BF4)2 (10) with the ligand acting as a six-electron donor involving phosphorus and two triazole nitrogen atoms. The copper complexes of 2 and 3 containing rhomboid Cu2X2 units, [(Cu)2(μ-X)2{o-Ph2P(C6H4){1,2,3-N3C(Ph)C(H)}-κ-P}2] (4, X = Cl; 5, X = Br), on treatment with 1,10-phenanthroline and 2,2'-bipyridine gave mixed-ligand complexes of the type [(CuX)(N∩N-κ(2)-N,N){o-Ph2P(C6H4){1,2,3-N3C(Ph)C(H)}-κ-P}] (N∩N = 1,10-phen and 2,2'-bipy; X = Cl, Br, and I).

The synthesis and coordination complexes of the new 1,2,3‐triazole phosphinite Ph2POCH2CH2[1,2,3‐N3C(Ph)C(H)] (2) are described. Compound 2 reacts with H2O2, S8, and Se8 to afford the chalcogenides Ph2P(=E)OCH2CH2[1,2,3‐N3C(Ph)C(H)] [E = O (3), S (4), and Se (5)]. The reaction of 2 with [Ru(η6‐cymene)Cl2] yielded [Ru(η6‐cymene)Cl2(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})] (6), which produced [Ru(η6‐cymene)(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})]2[OTf]2 (7) on further treatment with silver triflate (AgOTf); in 7, 2 acts as a bidentate (P,N) ligand. The reaction of 2 with [CpRuCl(PPh3)2] (Cp = cyclopentadienyl) in 1:1 and 1:2 molar ratios afforded the mono‐ and disubstituted complexes [CpRuCl(PPh3)(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})] (8) and [CpRuCl(Ph2P‐OCH2CH2{1,2,3‐N3C(Ph)C(H)})2] (9), respectively. Complex 9 reacted with silver triflate to yield the cationic complex [CpRu(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})][OTf] (10), in which one of the phosphinite ligands shows P,N‐chelation. The reactions of 2 with [M(COD)Cl2] (M = Pd, Pt; COD = 1,5‐cyclooctadiene) in 2:1 ratios yielded cis‐[MCl2(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})2] [M = Pd (11) and Pt (12)]. The similar reaction of 2 with [PdCl(η3‐C3H5)]2 in a 2:1 ratio afforded [PdCl(η3‐C3H5)(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})] (13). The reaction of 2 with [AuCl(SMe2)] in a 1:1 ratio yielded [Au(Cl)(Ph2POCH2CH2{1,2,3‐N3C(Ph)C(H)})2] (14). The molecular structures of 6, 7, 9, 11, and 12 were determined by single‐crystal X‐ray studies.

Invited for the cover of this issue is MaravanjiàS. Balakrishna from the Indian Institute of Technology Bombay, India. The cover image shows the new triazole‐based phosphinite ligand and its ability to stabilize various coordination modes.

Designing efficient phosphorus-based ligands to make catalysts for homogeneous catalysis has been a great challenge for chemists. Despite a plethora of phosphorus ligands ranging from simple tertiary phosphines to polyphosphines are known, the enthusiasm to generate new ones is mainly due to the demand from industry for economical and robust catalytic system operational under normal atmospheric conditions. In this context, we have developed new synthetic methodologies for making unusual inorganic ring systems containing trivalent phosphorus centres, novel phosphorus-based multidentate and hybrid ligands and explored their rich transition metal chemistry and catalytic applications. We have also fine tuned a few existing ligand systems with donor functionalities to employ them in homogeneous catalysis. The details are summarized in this account.

The Front Cover shows the new triazole‐based phosphinite ligand and its coordination versatility. It shows monodentate, bridging, and chelating bidentate modes of coordination with transition metal derivatives. This ambidentate ligand with two nitrogen and one phosphorus donor atoms is very useful to stabilize low‐valent metals – an ideal candidate for catalytic investigations. More information can be found in the https://doi.org/10.1002/ejic.201701058 For more on the story behind the cover research, see the https://doi.org/10.1002/ejic.201800309.