Synthesis, structures and luminescent behaviour of tridentate salicylaldiminato-type borate complexes

Treatment of the ligands 3,5-tBu₂-2-(OH)C₆H₂CHNR [R = 2-(CO₂H)C₆H₄ (1a) and 2-(CO₂H)C₁₀H₆ (1b)] with trimethylborate, B(OMe)₃, in toluene yields, after work-up, the yellow crystalline complexes {[3,5-tBu₂-2-(O)C₆H₂CHNR]B(OMe)} [R = 2-(CO₂)C₆H₄ (2a) and 2-(CO₂)C₁₀H₆ (2b)], respectively. Further treatment of these complexes with trifluoromethanesulfonic (triflic) acid, CF₃SO₃H, followed by recrystallisation from tetrahydrofuran (thf) afforded the triflate salts [{3,5-tBu₂-2-(O)C₆H₂CHNR}B(thf)][CF₃SO₃] [R = 2-(CO₂)C₆H₄ (3a) and 2-(CO₂)C₁₀H₆ (3b)]. An electroluminescent device was constructed using 2a, which produced orange-green light with broad emission spectra (maximum brightness of 5 cd/m² being observed at 13 V). Compounds 1a and 2b·2MeCN have been characterised by single crystal X-ray structure determinations.     

New phospholyl complexes of groups 4 and 6: Syntheses, characterisation and polymerisation studies

[M(P₃C₂^tBu₂)(CO)₃I] (M = Mo, 1, W, 2) have been synthesised and reacted with PCl₅ for oxidation study purposes. Compounds Ti(P₃C₂^tBu₂)(Ind)Cl₂], 3, and [Zr(P₃C₂^tBu₂)(Cp)Cl₂], 4, were detected spectroscopically, but showed to be too unstable to be isolated. A Ti(IV) complex, [Ti(P₃C₂^tBu₂)Cl₃], 5, has been formed from the reaction of [TiCl₄] with the base-free ligand K(P₃C₂^tBu₂), while the Ti(III) species, [Ti(P₃C₂^tBu₂) Cl₂(THF)], 6, was prepared from [TiCl₃(THF)₃]. Compounds 5 and 6 were studied as ethylene catalyst precursors after activation with MAO. In the studied conditions, complex 5 is the most active one with an activity of 2.2 × 10⁵ g(molTi [E] h)⁻¹, one order of magnitude higher than compound 6. The produced polymer is linear polyethylene.     

Synthesis and structures of aryloxo- and binaphthoxogermanium(IV) alkyl iodide complexes

The germanium(II) aryloxide complexes (S)-[Ge{O₂C₂₀H₁₀-(SiMe₂Ph)₂-3,3′}{NH₃}] (1) and [Ge(OC₆H₃Ph₂-2,6)₂] (2) react with either Bu^tI or MeI to yield the corresponding germanium(IV) compounds (S)-[Ge{O₂C₂₀H₁₀-(SiMe₂Ph)₂-3,3′}{Bu^t}{I}] (3), (S)-[Ge{O₂C₂₀H₁₀-(SiMe₂Ph)₂-3,3′}{Me}{I}] (4), [Ge(OC₆H₃Ph₂-2,6)₂(Bu^t)(I)] (5), and [Ge(OC₆H₃Ph₂-2,6)₂(Me)(I)] (6). Compound 6 reacts with 2,6-diphenylphenol to yield [Ge(OC₆H₃Ph₂-2,6)₃(Me)] (7), while 3-5 do not. The X-ray crystal structures of 3-5 and 7 were determined, and 3-5 represent the first structurally characterized germanium(IV) species having germanium bound to both oxygen and iodine.     

sp C-H and sp C-H agostic ruthenium complexes: a combined experimental and theoretical study

Halide abstraction from the 18 electron Ru(II) complex RuCl(CO)₂[2,6-(CH₂P^tBu₂)₂C₆H₃] (2) with AgPF₆ results in the exclusive formation of the cationic complex {Ru(CO)₂[2,6-(CH₂P^tBu₂)₂C₆H₃]}⁺PF₆⁻ (3). The molecular structures of 2 and 3 were determined by complete single-crystal diffraction studies. X-ray crystallographic analysis of 3 reveals that the “open” coordination site is occupied by an agostic interaction between the metal center and an sp³ C-H bond of a tert-butyl substituent. DFT gas phase calculations (B97-1/SDD) show the necessity of two sterically demanding tert-butyl substituents on one P donor atom for the agostic interaction to occur. The reaction of 3 with H₂ results in the quantitative conversion to {Ru(H)(CO)₂[2,6-(CH₂P^tBu₂)₂C₆H₄]}⁺PF₆⁻ (4) where the aromatic C_ipso-H bond is η²-coordinated to the metal center. Treatment of the agostic complex 4 with Et₃N results in the formation of the neutral complex Ru(H)(CO)₂[2,6-(CH₂P^tBu₂)₂C₆H₃] (5). The mechanistic details of 3 + H₂ → 4 were investigated by DFT calculations at the B97-1/SDB-cc-pVDZ//B97-1/SDD level of theory.     

Niobium-based ethylene polymerization procatalysts bearing di- and triphenolate ligands

Interaction of [NbCl₅] with the diphenol 2,2′-CH₃CH[4,6-(Bu^t)₂C₆H₂OH]₂ (LH₂) affords, after work-up, the red crystalline complex [NbCl(NCMe)L₂] (1). Under similar conditions, [NbOCl₃] and the sulfur-bridged diphenol 2,2′-S[4,6-(Bu^t)₂C₆H₂OH]₂ (L^SH₂) afford the orange complex [NbCl(L^S)₂] (2). Crystal structure determinations of 1 · 2MeCN and 2 reveal monomeric 6- and 7-coordinate complexes, respectively. The polymerization behaviour of 1 and 2 towards ethylene, in the presence of alkylaluminium co-catalysts has been examined and has been compared with that of the known niobium aryloxides [Nb(Me-L²)Cl₂]₂ (3), {Nb[(Bu^t-L²)H]₂Cl(NCMe)} (4) and [Nb(Bu^t-L²)Cl₂] (5), derived from the linear-linked aryloxide trimers 2,6-bis(4,6-dimethylsalicyl)-4-tert-butylphenol [(Me-L²)H₃] and 2,6-bis(4-methyl-6-tert-butylsalicyl)-4-tert-butylphenol [(Bu^t-L²)H₃]. The crystal structure of the acetonitrile solvate of 3 · 4MeCN, is also reported.     

Mononuclear and dinuclear model hydrolases of nickel and cobalt

Reaction between the dinuclear model hydrolases [M₂(μ-OAc)₂(OAc)₂(μ-H₂O)(tmen)₂]; M = Ni (1); M = Co (2) and trimethylsilyltrifluoromethanesulphonate (TMS-OTf) under identical reaction conditions gives the mononuclear complex [Ni(OAc)(H₂O)₂(tmen)][OTf] · H₂O (3) in the case of nickel and the dinuclear complex [Co₂(μ-OAc)₂(μ-H₂O)₂(tmen)₂][OTf]₂ (4) in the case of cobalt.Reaction of (3) with urea gives the previously reported [Ni(OAc)(urea)₂(tmen)][OTf] (5), whereas (4) gives [Co₂(OAc)₃(urea)(tmen)₂][OTf] (6) previously obtained by direct reaction of (2) with urea. Both (3) and (4) react with monohydroxamic acids (RHA) to give the dihydroxamate bridged dinuclear complexes [M₂(μ-OAc)(μ-RA)₂(tmen)₂][OTf]; M = Ni (7); M = Co (8) previously obtained by the reaction of (1) and (2) with RHA, illustrating the greater ability of hydroxamic acids to stabilize dinuclear complexes over that of urea by means of their bridging mode, and offering a possible explanation for the inhibiting effect of hydroxamic acids by means of their displacing bridging urea in a possible intermediate invoked in the action of urease.     

Synthesis, crystal structures, electrochemical and magnetic properties of polynuclear {Fe4} and {Fe8Na4} carboxylate/picolinate clusters

Reaction of sodium picolinate with Fe^III oxo-centered carboxylate triangles in MeCN in the presence of PPh₄Cl yields (PPh₄)[Fe₄O₂(O₂CR)₇(pic)₂] (R = Ph (1), Bu^t (2)). Omitting the phosphonium cation produces [Fe₈Na₄O₄(O₂CPh)₁₆(pic)₄(H₂O)₄] (3), which contains two Fe₄Na₂ units bridged by two picolinate ligands. X-ray crystal structures of 1 and 3 are reported.Voltammetric profiles in MeCN show four one-electron reduction steps for complexes 1 and 2. Variable-temperature magnetic susceptibility measurements in polycrystalline samples of 1 and 3 reveal strong antiferromagnetic couplings leading to S = 0 ground states.     

Synthesis, characterization and in vitro antitumor activity of three organotin(IV) complexes with carbazole ligand

Three novel organotin(IV) complexes with 2-(9H-carbazol-9-yl) acetic acid (HL), of the formulae {[nBu₂SnOL]₂O}₂ (1), [nBuSn(O)OL]₆ (2) and [nBu₃SnOL]₆ (3) were prepared. All compounds were characterized by X-ray crystallography, confirming that complex (1) is tetranuclear one with ladder framework, complex (2) is a hexanuclear organotin(IV) complex with drum structure and complex (3) is a macrocycle with 24-membered stannoxane ring. Furthermore, all complexes were tested in vitro for their cytotoxic activity, using human hepatocellular carcinoma cell line (BEL-7402) and human hepatocellular liver carcinoma cell line (HepG2). Complex (1) displayed the best cytotoxicity and can be pointed out as a promising substrate to be subject of further investigations.     

Hyponitrite complexes: Crystal and molecular structure of [Ru2(CO)4(μ-PBu2)(μ-Ph2PCH2PPh2)(μ-η-ONNOMe)]

The new trans-hyponitrite derivative complex [Ru₂(CO)₄(μ-P^tBu₂)(μ-dppm)(μ-η²-ONNOMe)] (2, dppm = Ph₂PCH₂PPh₂) was prepared by deprotonation of [Ru₂(CO)₄(μ-H)(μ-P^tBu₂)(μ-dppm)(μ-η²-ONNOMe)][BF₄] (1) with the base DBU (1.8-diazabicyclo[5.4.0]undec-7-ene). The latter complex salt has been obtained in an improved synthesis starting from the trans-hyponitrite complex [Ru₂(CO)₄(μ-H)(μ-P^tBu₂)(μ-dppm)(μ-η²-ONNO)]. Compound 2 has been characterized by spectroscopic methods as well as by X-ray diffraction and represents the first neutral complex bearing a deprotonated monoester of the hyponitrous acid as the bridging ligand.     

Synthesis and structures of copper and gold complexes of the P,N ligands RNC(Bu)C(H)RPPh2 (R = SiMe3, H)

The reaction of the chelating P,N ligand RNC(Bu^t)CH(R)PPh₂ (R = SiMe₃) (1) with CuCl and CuCl₂ (probably by way of reduction to Cu(I) by the phosphine ligand) or Cu(NCCH₃)₄ClO₄ yielded the dimeric 1:1 complex [Cu{PPh₂CH(R)C(Bu^t)NR}Cl]₂ (2) or the monomeric 2:1 complex [Cu{PPh₂CH(R)C(Bu^t)NR}₂]ClO₄ (3), respectively. The presence of trace amounts of water during the reaction resulted in the successive cleavage of the two trimethylsilyl groups of the ligand and the formation of the monomeric chelate complexes [Cu{PPh₂CH(R)C(Bu^t)NH}₂]ClO₄ (4) and [Cu{PPh₂CH₂C(Bu^t)NH}₂]ClO₄ (5). Oxidation of 5 by atmospheric oxygen led to small quantities of the blue Cu(II) complex [Cu{(O)PPh₂CH₂C(Bu^t)NH}₂](ClO₄)₂ (6). The dimeric gold complexes [Au{PPh₂CH₂C(Bu^t)NH}]₂X₂ (X = BF₄, ClO₄) (7) were similarly obtained from the previously described Au{PPh₂CH(R)C(Bu^t)NR}Cl by replacing the covalently bound chlorine with the weakly coordinating anions in the presence of small quantities of water. The solution and solid state structures (except 5) of all complexes were determined by NMR spectroscopy and X-ray crystallography.     

Synthesis, structure and properties of TTF-carboxylate bridged paddlewheel dirhodium complexes, Rh2(BuCO2)3(TTFCO2) and Rh2(BuCO2)2(TTFCO2)2

Reaction of tetrathiafulvalene carboxylic acid (TTFCO₂H) with paddlewheel dirhodium complex Rh₂(Bu^tCO₂)₄ yielded TTFCO₂-bridged complexes Rh₂(Bu^tCO₂)₃(TTFCO₂) (1) and cis- and trans-Rh₂(Bu^tCO₂)₂(TTFCO₂)₂ (cis- and trans-2). Their triethylamine adducts [1(NEt₃)₂] and cis-[2(NEt₃)₂] were purified and isolated with chromatographic separation, and characterized with single crystal X-ray analysis. Trans-[2(NEt₃)₂] is not completely separated from a mixture of cis- and trans-[2(NEt₃)₂], but its single crystals were obtained from a solution of the mixture. A three-step quasi-reversible oxidation process was observed for 1 in MeCN. The first two steps correspond to the oxidation of the TTFCO₂ moiety and the last one is the oxidation of the Rh₂ core. The oxidation of cis-2 is observed as a two-step process with very similar E_1/2 values to those of the first two processes for 1. Both 1⁺ and cis-2²⁺ in MeCN at room temperature show isotropic ESR spectra with a g value of 2.008 and a_H = 0.135 mT for two equivalent H atoms and a_H = 0.068 mT for one H atom. The redox and ESR data of cis-2 suggest that the intramolecular interaction between the TTF moieties is very small.     

Synthesis and reactivity of imido niobium complexes containing the functionalized (dichloromethylsilyl)cyclopentadienyl ligand

The niobium complex [NbCp^ClCl₄] (Cp^Clη⁵-C₅H₄(SiCl₂Me)) (1) with a functionalized (dichloromethylsilyl)cyclopentadienyl ligand was isolated by the reaction of [NbCl₅] with C₅H₄(SiCl₂Me)(SiMe₃). Complex 1 was a precursor for the imido silylamido derivative [NbCp^NCl₂(NtBu)] (Cp^Nη⁵-C₅H₄[SiClMe(NHtBu)]) (2) after addition of LiNHtBu, which subsequently gave the dichlorosilyl compound [NbCp^ClCl₂(NtBu)] (3) when reacted with SiCl₃Me. Addition of LiNHtBu to complex 2 gave the niobium amido complex [NbCp^NCl(NHtBu)(NtBu)] (4), which slowly evolved with exchange of the niobium-amido and the silicon-chloro groups to give the dichloroniobium complex [NbCp^NNCl₂(NtBu)] (Cp^NNη⁵-C₅H₄[SiMe(NHtBu)₂]) (5). Reaction of 2 with excess LiNHtBu gave the silyl-η-amido constrained geometry complexes [Nb{η⁵-C₅H₄[SiMe(NHtBu)(-η-NtBu)]}(NHtBu)(NtBu)] (6) and [Nb{η⁵-C₅H₄[SiClMe(-η-NtBu)]}(NHtBu)(NtBu)] (7), whereas addition of one equimolecular amount of LiNHtBu to 5 in C₆D₆ afforded complex [NbCp^NNCl(NHtBu)(NtBu)] (8). All of the new complexes were characterized by ¹H, ¹³C and ²⁹Si NMR spectroscopy.     

Synthesis and reactivity of osmium (VI) nitrido complexes containing pyridine-carboxylato ligands

A series of osmium(VI) nitrido complexes containing pyridine-carboxylato ligands Os^VI(N)(L)₂X (L = pyridine-2carboxylate (1), 2-quinaldinate (2) and X = Cl (a), Br (1b and 2c) or CH₃O (2b)) and [Os^VI(N)(L)X₃]⁻ (L = pyridine-2,6-dicarboxylate (3) and X = Cl (a) or Br (b)) have been synthesised. Complexes 1 and 2 are electrophilic and react readily with various nucleophiles such as phosphine, sulfide and azide. Reaction of Os^VI(N)(L)₂X (1 and 2) with triphenylphosphine produces the osmium(IV) phosphiniminato complexes Os^VI(NPPh₃)(L)₂X (4 and 5). The kinetics of nitrogen atom transfer from the complexes Os^VI(N)(L)₂Br (2c) (L = 2-quinaldinate) with triphenylphosphine have been studied in CH₃CN at 25.0 °C by stopped-flow spectrophotometric method. The following rate law is obtained: −d[Os(VI)]/dt = k₂[Os(VI)][PPh₃]. Os^VI(N)(L)₂Cl (L = 2-quinaldinate) (2a) reacts also with [PPN](N₃) to give an osmium(III) dichloro complex, trans-[PPN][Os^III(L)₂Cl₂] (6). Reaction of Os^VI(N)(L)₂Cl (L = 2-quinaldinate) (2a) with lithium sulfide produces an osmium(II) thionitrosyl complex Os^II(NS)(L)₂Cl (7). These complexes have been structurally characterised by X-ray crystallography.     

Metal ion size and coordination mode in complexes of a β-diketiminate ligand with pendant quinoline arms

A suite of late first row transition metal complexes has been synthesized using a monoanionic nitrogen donor β-diketiminate ligand with quinolyl pendant arms, BDI^QQH (1). BDI^QQNiOTf (2), BDI^QQCuCl (4), BDI^QQZnCl (5) were prepared from the reaction of 1 with Ni(OTf)₂, CuCl₂·2H₂O and ZnCl₂, respectively. BDI^QQNiCl (3) was synthesized from an anion exchange of 2 with ⁿBu₄NCl. Reaction of 1 and CoI₂ afforded the unexpected [(BDI^QQ)₂Co]⁺I⁻ (6). Through density functional theory (DFT) calculations, ligand geometries in BDI^QQ complexes were investigated and it was found that smaller ionic radius and higher charge destabilize 1:1 metal-ligand complexes relative to alternative 1:2 complexes like 6 owing to significant conformational strain in 1:1 complexes involving metals with small ionic radii. Synthesis and characterization of these complexes, including crystal structures of 4 and 5, are reported, in addition to the results of DFT calculations.     

Syntheses and structures of lanthanide complexes containing a bis(imidazolin-2-imino)pyridine pincer ligand

The Lewis acid-base reaction of 2,6-bis[1,3-di-tert-butylimidazolin-2-imino)methyl]pyridine (TL^tBu) and LnCl₃ in THF leads to the corresponding neutral lanthanide complexes of type [(TL^tBu)LnCl₃], Ln = Y (1a), Er (1b), Lu (1c). The yttrium and lutetium complexes have been characterized by X-ray diffraction analysis. The solid state structures reveal that the bulky TL^tBu ligand causes steric crowding around the lanthanide atoms by coordinating to the metal center in a tridentate fashion. In addition, remote C-H?Ln interactions (H?Ln ca. 2.7 Å) involving one of the ^tBu methyl groups are observed in both cases. A DFT (density functional theory) calculation on 1a was able to reproduce this interaction, which was additionally characterized by means of an H?Y compliance constant and by employing the AIM (atoms in molecules) theory.     

Acid-base behavior of a simple metal bis(dithiolate) system: Synthesis, crystal structure and spectroscopy of [Bu4N]2[M(ppdt)2] (M = Ni, Pt; ppdt = pyrido[2,3-b]pyrazine-2,3-dithiolate)

The syntheses, crystal structures and properties of compounds [Bu₄N]₂[Ni(ppdt)₂] (1) and [Bu₄N]₂[Pt(ppdt)₂] (2) (ppdt = pyrido[2,3-b]pyrazine-2,3-dithiolate) have been described. Compound 1 crystallizes in P2₁/c space group (monoclinic system), whereas compound 2 crystallizes in C2/c space group (monoclinic system). The crystal structures of both compounds 1 and 2 have been characterized by C-H?S and C-H?N hydrogen bonding interactions between cation and anions resulting in three-dimensional supramolecular networks in the crystals of 1 and 2, respectively. The acid-base behavior of the ground states of both [Bu₄N]₂[Ni(ppdt)₂] (1) and [Bu₄N]₂[Pt(ppdt)₂] (2) and also the excited state of compound [Bu₄N]₂[Pt(ppdt)₂] (2) in solutions has been studied. The pH dependent changes in the charge transfer absorption and emission spectra are attributed to the protonation on an imine nitrogen of the ppdt ligand. The ground-state basicity constants of the two complexes 1 and 2 have been determined from spectrophotometric analysis by titrating with an weak acid, yielding pK_b1 = 8.0 for complex [Bu₄N]₂[Ni(ppdt)₂] (1) and pK_b1 = 7.8 for complex [Bu₄N]₂[Pt(ppdt)₂] (2). The excited-state basicity constant pK_b1^* for complex [Bu₄N]₂[Pt(ppdt)₂] (2) has been determined by a thermodynamic equation using a Förster analysis yielding the value of 1.8. The complex 2 is electrochemically irreversible with an oxidation potential of E_1/2 = +0.41 V versus Ag/AgCl in methanol.     

Synthesis, protonation and electrochemical properties of trinuclear NiFe2 complexes Fe2(CO)6(μ3-S)2[Ni(Ph2PCH2)2NR] (R = n-Bu, Ph) with an internal pendant nitrogen base as a proton relay

Two trinuclear NiFe₂ complexes Fe₂(CO)₆(μ₃-S)₂[Ni(Ph₂PCH₂)₂NR] (R = n-Bu, 1; Ph, 2) containing an internal base were prepared as biomimetic models for the active sites of FeFe and NiFe hydrogenases. Treatment of complex Fe₂(CO)₆(μ₃-S)₂[Ni(Ph₂PCH₂)₂N(n-Bu)] (1) with HOTf gave an N-protonated complex [Fe₂(CO)₆(μ₃-S)₂{Ni(Ph₂PCH₂)₂NH(n-Bu)}][OTf] ([1H][OTf]). The structures of complexes 1, 2 and [1H][OTf] were determined by X-ray crystallography, which shows that the proton held by the N atom of [1H][OTf] lies in an equatorial position. Cyclic voltammograms of complexes 1 and [1H][OTf] were studied and compared with that of Fe₂(CO)₆(μ₃-S)₂[Ni(dppe)].     

Reaction of carbon monoxide with tri-tert-butylgallium: The first example of CO insertion into a gallium-carbon bond

Reactions of ^tBu₃M (M = Al, Ga) with CO have been studied by density functional theory employing the B3PW91 functional. Calculations suggest that CO insertion into a M-C bond of ^tBu₃M is thermodynamically favorable at room temperature, whereas CO coordination to ^tBu₃M to form ^tBu₃M·CO is unfavorable due to an unfavorable entropy change. These results are in agreement with experimental observations. Reaction of carbon monoxide with ^tBu₃Ga at 50 °C and atmospheric pressure yields the dimeric tert-butylacyl complex [^tBu₂GaC(O)^tBu]₂ (1). Compound 1 has been characterized by X-ray crystallography and NMR and IR spectroscopy. Isotopic labeling with ¹³CO confirmed that the acyl carbon of 1 results from the CO starting material. CO insertion into a Ga-C bond does not occur for Me₃Ga or ⁿBu₃Ga under a range of reaction conditions.     

Arene-Ru(II)-chloroquine complexes interact with DNA, induce apoptosis on human lymphoid cell lines and display low toxicity to normal mammalian cells

The complexes [Ru(η⁶-p-cymene)(CQ)Cl₂] (1), [Ru(η⁶-benzene)(CQ)Cl₂] (2), [Ru(η⁶-p-cymene)(CQ)(H₂O)₂][BF₄]₂ (3), [Ru(η⁶-p-cymene)(en)(CQ)][PF₆]₂ (4), [Ru(η⁶-p-cymene)(η⁶-CQDP)][BF₄]₂ (5) (CQ = chloroquine base; CQDP = chloroquine diphosphate; en = ethylenediamine) interact with DNA to a comparable extent to that of CQ and in analogous intercalative manner with no evidence for any direct contribution of the metal, as shown by spectrophotometric and fluorimetric titrations, thermal denaturation measurements, circular dichroism spectroscopy and electrophoresis mobility shift assays. Complexes 1-5 induced cytotoxicity in Jurkat and SUP-T1 cancer cells primarily via apoptosis. Despite the similarities in the DNA binding behavior of complexes 1-5 with those of CQ the antitumor properties of the metal drugs do not correlate with those of CQ, indicating that DNA is not the principal target in the mechanism of cytotoxicity of these compounds. Importantly, the Ru-CQ complexes are generally less toxic toward normal mouse splenocytes and human foreskin fibroblast cells than the standard antimalarial drug CQDP and therefore this type of compound shows promise for drug development.     

Pyridine and phosphine reactions with [CPh3][B(C6F5)4]

Trityl borate salts [4-RPyCPh₃][B(C₆F₅)₄] (R = H 1, ^tBu 2, Et 3, NMe₂4) and [R₃PCPh₃][B(C₆F₅)₄] (R = Me 5, ⁿBu 6, Ph[1] 7, p-MeC₆H₄8) are readily prepared via equimolar reaction of the appropriate pyridine or phosphine and trityl borate [CPh₃][B(C₆F₅)₄]. The analogous reactions of PⁱPr₃ affords the product [(p-ⁱPr₃P-C₆H₄)Ph₂CH][B(C₆F₅)₄] (9) while the corresponding reactions of Cy₃P and ^tBu₃P gave the cyclohexadienyl derivatives [(p-R₃PC₆H₅)CPh₂][B(C₆F₅)₄] (R = Cy 10, ^tBu 11). X-ray structures of 5 and 9 are reported.