Role of Anions and Mixtures of Anions on the Thermochromism, Vapochromism, and Polymorph Formation of Luminescent Crystals of a Single Cation, [(CHNC)Au].

Noncoordinating anions, which generally play a subordinate role in coordination chemistry, alter the structure, the luminescence, as well as the thermochromic and vapochromic behaviors of salts of the two-coordinate cation, [(CHNC)Au]. Thus whereas the yellow polymorphs of [(CHNC)Au](PF) and [(CHNC)Au](AsF) contain single chains of cations and are vapochromic, yellow [(CHNC)Au](SbF) does not form the same polymorph and is not vapochromic but contains two distinct chains of cations connected through aurophilic interactions. Mixed crystals such as [(CHNC)Au](PF)(AsF) have been prepared by adding diethyl ether to a dichloromethane solution containing equimolar amounts of [(CHNC)Au](PF) and [(CHNC)Au](AsF).

Crystallization and interconversions of vapor-sensitive, luminescent polymorphs of [(C6H11NC)2Au(I)](AsF6) and [(C6H11NC)2Au(I)](PF6).

The remarkable, vapor-induced transformation of the yellow polymorphs of [(C(6)H(11)NC)(2)Au(I)](AsF(6)) and [(C(6)H(11)NC)(2)Au(I)](PF(6)) into the colorless forms are reported along with related studies of the crystallization of these polymorphs. Although the interconversion of these polymorphs is produced by vapor exposure, molecules of the vapor are not incorporated into the crystals. Thus, our observations may have broad implications regarding the formation and persistence of other crystal polymorphs where issues of stability and reproducibility of formation exist.

A reversible polymorphic phase change which affects the luminescence and aurophilic interactions in the gold (I) cluster complex, [mu3-S(AuCNC7H13)3](SbF6).

Crystallographic examination of [mu3-S(AuCNC7H13)3](SbF6) shows that it undergoes a reversible phase change from orthorhombic to monoclinic upon cooling. At 190 K, the structure shows that two cations self-associate to form a pseudo-octahedral array of six gold atoms connected by both intra- and interionic aurophilic interactions. On cooling, the clusters become less symmetric, and in one, the interionic Au.

Pyridine substituted N-heterocyclic carbene ligands as supports for Au(I)-Ag(I) interactions: formation of a chiral coordination polymer.

Reaction of 1,3-bis(2-pyridinylmethyl)-1H-imidazolium tetrafluoroborate, [H(pyCH(2))(2)im]BF(4), with silver oxide in dichloromethane readily yields [Ag((pyCH(2))(2)im)(2)]BF(4), 1.BF(4)(). 1.

Mixed-metal metallocryptands. Short metal-metal separations strengthened by a dipolar interaction.

The deep-red, air-stable mixed-metal metallocryptands, [AuPdTl(P2phen)3](PF6)2, 1.(PF6)2, and [AuPtTl(P2phen)3](PF6)2, 2.(PF6)2, are easily prepared in good yield (60-70%) by reacting 3 equiv of P2phen with 1 equiv of Au(THT)Cl, excess thallous acetate, and the appropriate amount of either Pd2(dba)3 for 1 or Pt(dba)2 for 2 in acetonitrile where P2phen is 2,9-bis(diphenylphosphino)-1,10-phenanthroline, THT is tetrahydrothiophene, and dba is dibenzylidineacetone.

Short metal-metal separations in a highly luminescent trimetallic Ag(I) complex stabilized by bridging NHC ligands.

Reaction of 1,3-bis(2-pyridinylmethyl)-1H-imidazolium salt, [H(pyCH(2))(2)im]X (X = BF(4)(-) or Cl(-)), with silver oxide in acetonitrile readily yields yellow-brown [((pyCH(2))(2)im)(2)Ag]X, 1.BF(4) or 1.Cl.

Three- and four-coordinate gold(I) complexes of 3,6-bis(diphenylphosphino)pyridazine: monomers, polymers, and a metallocryptand cage.

The slightly yellow polymeric complexes [Au(2)Cl(2)(P(2)pz)(3)](n), 1 x 6CHCl(3), (P(2)pz is 3,6-bis(diphenylphosphino)pyridazine) and [[Au(2)(P(2)pz)(3)](PF(6))(2)](n), 2, are prepared by the stoichiometric reaction of AuCl(tht) (tht is tetrahydrothiophene) and P(2)pz in either dichloromethane or dichloromethane/methanol, respectively. Addition of 2 equiv of AuCl(tht) to a dichloromethane solution of 1 equiv of P(2)pz generates the simple (AuCl)(2)(P(2)pz) compound, 3. Compound 3 contains nearly linear P-Au-Cl units with intermolecular Au.

Pd(0) and Pt(0) metallocryptands encapsulating a spinning mercurous dimer.

The deep-red, air-stable complexes [Pt(2)Hg(2)(P(2)phen)(3)](PF(6))(2), 1, or [Pd(2)Hg(2)(P(2)phen)(3)](PF(6))(2), 2, (P(2)phen is 2,9-bis(diphenylphosphino)-1,10-phenanthroline) are most conveniently prepared by the stoichiometric reaction of either Pt(dba)(2) or Pd(2)(dba)(3).CHCl(3) (dba is dibenzylideneacetone) with P(2)phen and a single drop of elemental mercury in refluxing dichloromethane under an atmosphere of nitrogen. The (31)P[(1)H] NMR spectrum (CD(3)CN) of 1 shows a single sharp resonance at 43.