Pyrazolyl Ring Research Articles

An Example of Polynomial Expansion: The Reaction of 3(5)-Methyl-1H-Pyrazole with Chloroform and Characterization of the Four Isomers.

The reaction in phase-transfer catalyzed conditions of 3(5)-methyl-1H-pyrazole with chloroform affords four isomers 333, 335, 355 and 555 in proportions corresponding to the polynomial expansion (a + b)3, with a = 0.6 and b = 0.4, a and b being 3-methyl and 5-methyl proportions. The up (u) and down (d) conformation of the pyrazolyl rings with regard to the Csp3–H atom was established by X-ray crystallography and by 1H-, 13C- and 15N-NMR in solution combined with gauge-including atomic orbitals (GIAO)/B3LYP/6-311++G(d,p) calculations. A comparison with other X-ray structures of tris-pyrazolylmethanes was carried out.

N′-[5-Acetyl-3-(4-chlorophenyl)-2,3-dihydro-1,3,4-thiadiazol-2-ylidene]-5-(1H-indol-3-yl)-1-phenyl-1H-pyrazole-3-carbohydrazide dimethylformamide monosolvate

In the title solvate, C28H20ClN7O2S·C3H7NO, the main molecule consists of chlorophenyl (A), thiadiazolyl (B), pyrazolyl (C), phenyl (D) and indolyl (E) rings, with twist angles between neighbouring rings A/B, B/C, C/D and D/E of 32.6 (1), 14.8 (1), 60.8 (1) and 20.1 (1)°, respectively. The dimethylformamide solvent molecule accepts an N—H...O hydrogen bond from the indole group. In the extended structure, molecules related by 21 screw axes are stacked in the [001] direction to form columns linked by weak C—H...O interactions.

Crystal Structure of the Chiral Azomethine Imine, (Z)-(S)-4-(tert-Butylcarbonylamino)-2-(2-methoxybenzylidene)-5-oxopyrazolidin-2-ium-1-ide, Obtained by the Cyclization of tert-Butyl (S)-2-[2-(methoxybenzylidene)hydrazine]-1-(hydroxymethyl)-2-oxocarbamate

Further study of the cyclization reactions of (S)-t-BuOCH2CONHCH(CH2OH)CONHN = Ar, derived from (l)-serine, has found that reaction with MeI/K2CO3 in Me2CO produces (Z)-(S)-4-(tert-butylcarbonylamino)-2-(benzylidene)-5-oxopyrazolidin-2-ium-1-ide, 3. We now wish to report the crystal structure of the 2-methoxybenzylidene derivative, 3a. While the pyrazolyl ring in 3a exhibits an envelope shape, with the flap at C5, the displacement of C5 from the best plane through the ring, however, is only 0.053(5) Å. The dihedral angle between the phenyl and pyrazolyl rings is 12.14(16)°. The pyrazolyl ring has a betaine character with opposite charges on N1 and N2 atoms. The supramolecular arrangement is created from one classical N–H···O and weaker C–H···X (X = O, N) intermolecular hydrogen bonds, each of which generate chains of molecules. Combinations of the (i) C19–H19A···O1 and C11–H11···O2 hydrogen bonds generates sheets of molecules in the ab plane, containing R44(40) rings, (ii) C18–H18B···O1 and C11–H11···O2 hydrogen bonds produce a two molecule wide column, containing R33(26) rings, propagated in the ac plane and (iii) C19–H19A···O1 and C15–H15A···N2 hydrogen bonds generate a different two molecule wide column, containing R33(26) rings, propagated in the ab plane. The compound crystallises in the orthorhombic space group, P212121, with a = 6.5906(5) Å, b = 10.9121(10) Å, c = 22.2080(17) Å, and Z = 4.Graphical The supramolecular array of the betaine compound, (Z)-(4S)-4-(tert-butyloxycarbonylamino)-3-oxo-1-(2-methoxybenzylidene)-pyrazolidinium inner salt, 3a, is created from one classical N–H···O and weaker C–H···X (X = O, N) intermolecular hydrogen bonds.

Tuning the O2 Binding Affinity of Cobalt(II) Centers by Changing the Structural and Electronic Properties of the Distal Substituents on Azole-Based Chelating Ligands.

The effects of the substituents on the chelating ligands located in the secondary coordination sphere on the O2 affinity of cobalt(II) centers have been explored. The combination of facially capping tridentate tris(pyrazolyl)borates (= TpMe2,4R) and bidentate bis(imidazolyl)borates (= [B(Im N-Me)2MeX]- ; LX) yields square-pyramidal cobalt(II) complexes. The structural properties of the substituent groups X attached to the boron center of LX affect the arrangement of X in the resulting cobalt(II) complexes [CoII(TpMe2,4R)(LX)]. When the boron-attached moiety of X is a relatively bulky sp3-CH2Y group (i.e., X:Y = Me:H and nBu: nPr), the alkyl group X faces the cobalt center, whereas for isopropoxy (O iPr) and phenyl (Ph) groups, of which the boron-attached atoms are a less hindered oxygen atom and a planer sp2-carbon, respectively, the X group is arranged away from the cobalt center. This flexible behavior of LX is reflected in the O2 affinity of the cobalt(II) center, which depends on the extent to which the complex sphere is shielded by the ligands. The dependence of the cobalt(II) oxidation potential on the X substituent of LX is inconsistent with the O2 affinity. On the other hand, the electronic properties of R, which is attached to the fourth position of the pyrazolyl rings in the rigid TpMe2,4R ligand, are reflected in the electrochemical properties and O2 affinity of the cobalt center.

An unexpected μ4-oxido-bridged tetranuclear Cu(II) inverse coordination complex of a heptadentate bis(pyrazolyl)methane-based ligand: Synthesis, structure, spectroscopic properties, and catecholase activity

A new tetranuclear copper(II) complex, {But-C6H2(O)[CH = N-CH2-CH(pz)2]2}2Cu4(μ4-O)(OAc)4 (L2Cu4(μ4-O)(OAc)4, pz = pyrazolyl ring) has been prepared from the condensation reaction of 4-tert-butyl-2,6-diformylphenol with two equivalents of bis(pyrazolyl)ethanamine moieties in the presence of two equivalents of copper(II) acetate. The complex has been characterized by X-ray diffraction studies in solid state, as well as by UV–Vis, IR, and ESI spectroscopies. The structure of this inverse coordination complex consists of a central oxygen ion surrounded by four copper(II) cations residing in the corners of a distorted tetrahedron; the remaining coordination sites of the Cu2+ ions are filled by imine donors and acetate counter-ions, leaving the bis(pyrazolyl)methane donor groups uncoordinated to the copper(II) centers. In contrast to the solid-state structure, this compound was found to be dinuclear in solution, LCu2(OAc)2(OH). The complex catalyzes the oxidation of 3,5-di-tert-butylcatechol (DTBC) and 4-tert-butylcatechol (TBC) to their corresponding quinones. The catalytic mechanism was investigated using DTBC as a substrate, and it was found that the oxidation reaction occurs via two different pathways, one involving molecular oxygen and the other hydrogen peroxide as oxidants.

Synthesis, spectroscopic characterization, x‐ray crystal structures, thermal behavior and antimicrobial activity of copper(II) complexes with the novel (3,5‐dimethyl‐1H‐pyrazol‐1‐yl)(morpholin‐4‐yl)methanethione

The new (3,5‐dimethyl‐1H‐pyrazol‐1‐yl)(morpholin‐4‐yl) methanethione ligand (L) and its copper(II) chelates Cu(L)Br2 (1), Cu(L)Cl2 (2) and [Cu(L)2OH(H2O)]ClO4·1.5H2O (3) have been prepared. The coordination behavior of the ligand and the properties of the chelate compounds have been investigated by several physico‐chemical techniques. The structures of (L), (1), and (2) have been characterized by x‐ray single crystal diffraction. The ligand (L) crystalizes in the monoclinic P21/n space group, a = 11.2632(4), b = 7.9959(2), c = 13.4337(5) Å, α = 90, β = 106.3080(14), γ = 90°. The copper(II) complexes (1) and (2) show a distorted square‐planar geometries, with the ligand behaves as a bidentates NS chelating agent, coordinating to the copper(II) ions through the N atom of the pyrazolyl ring and the thione S atom, the third and fourth coordination sites are occupied by two halogen (Br− or Cl−) ions. The ESR spectra of the prepared complexes are consistent with d(x2‐y2)1 ground state with axial symmetry. The thermal analysis data of the Cu(II) complexes (1 and 2) indicated that they have similar thermal degradation pathways. The complexes displayed antimicrobial activity against various pathogenic bacteria and fungi higher than that of the free organic ligand. The reaction of Cu(L)Cl2 (2) with pyridine (py) in ethanol at room temperature does not form mixed‐ligand complex, but leads to complete substitution of the ligand (L). The product of the substitution reaction was characterized based on elemental analyses and FT‐IR measurements.

Synthesis, characterization and antimicrobial activities of Co(III) and Ni(II) complexes with 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2): X-ray crystallography and DFT calculations of [Co(MPzNHex2)2]ClO4·1.5H2O (I) and [Ni(HMPzNHex2)2]Cl2·2H2O (II)

A new pyrazole containing ligand, 5-methyl-3-formylpyrazole-N(4)-dihexylthiosemicarbazone (HMPzNHex2), and a host of its cobalt(III) and nickel(II) complexes, [Co(MPzNHex2)2]X·mH2O and [Ni(HMPzNHex2)2]X2·nH2O (X = Cl, Br, ClO4, BF4 and NO3; m = 0 for Cl, Br, BF4 & NO3 and 1.5 for ClO4; n = 0 for Br, ClO4, BF4 & NO3 and 2 for Cl), respectively, have been synthesized and characterized by elemental analyses, magnetic measurements (polycrystalline state), 1H NMR (for the ligand and its Co(III) complexes), electronic and IR spectral parameters. All the reported Co(III) and Ni(II) complexes are cationic in nature and behaving as 1:1 and 1:2 electrolytes, respectively, in MeOH. Electronic spectral data of the complexes categorize them as having distorted octahedral coordination geometry. IR spectral features (4000–450 cm−1) specify a monodeprotonated/neutral tridentate (NNS) function of the ligand, HMPzNHex2 coordinating to the Co(III)/Ni(II) via the pyrazolyl (tertiary) ring nitrogen, azomethine nitrogen and thiolato/thioketo sulfur atom. 1H NMR spectral data (in CDCl3 at 400 MHz) for the primary ligand and those of its Co(III) complexes are in agreement with the proposition of bonding sites evidenced from IR data. The single crystal X-ray data of I (C2/c (#15); monoclinic) and II (P-1 (#2); triclinic) have confirmed a CoN4S2 and a NiN4S2 octahedral coordination, respectively. The pair of monoprotic/neutral coordinating ligands is more or less orthogonal to each other in the complex species. The data obtained from DFT calculations are reasonably in agreement with the UV–Vis spectral assignment and the structures of the complex species. Although the ligand and the tested metal ion complexes are capable of inhibiting microbial growth, the cobalt complexes can be promoted as better antimicrobial agents.

N-(6-Meth-oxy-pyridin-2-yl)-1-(pyridin-2-ylmeth-yl)-1H-pyrazole-3-carboxamide: crystal structure and Hirshfeld surface analysis.

The title compound, C16H15N5O2, adopts the shape of the letter L with the dihedral angle between the outer pyridyl rings being 78.37 (5)°; the dihedral angles between the central pyrazolyl ring (r.m.s. deviation = 0.0023 Å) and the methyl-ene-bound pyridyl and methyoxypyridyl rings are 77.68 (5) and 7.84 (10)°, respectively. Intra-molecular amide-N-H⋯N(pyrazol-yl) and pyridyl-C-H⋯O(amide) inter-actions are evident and these preclude the participation of the amide-N-H and O atoms in inter-molecular inter-actions. The most notable feature of the mol-ecular packing is the formation of linear supra-molecular chains aligned along the b-axis direction mediated by weak carbonyl-C=O⋯π(triazol-yl) inter-actions. An analysis of the calculated Hirshfeld surfaces point to the importance of H⋯H (46.4%), C⋯H (22.4%), O⋯H (11.9%) and N⋯H (11.1%) contacts in the crystal.

The Effect of Pyrazolyl Substituents on the Photophysical and Photochemical Properties of Pyrazine Derivatives.

The reaction of 2,5-dibromopyrazine with N-Lithium pyrazolate in a 1:2 ratio leads to a mixture of 2-bromo-5-(1H-pyrazol-1-yl)pyrazine (I) and 2,5-di(1H-pyrazol-1-yl)pyrazine (II). The structures of I and II are highly planar. Two absorption bands can be observed for the compounds in the UV-Vis region, having ε in the order of 104 m-1 cm-1 . TD-DFT computed results support the nature of the lower energy absorptions as πpyrazine →π*pyrazine transitions, including an additional intraligand charge transfer transition for I (πpyrazol →π*pyrazine ). Upon excitation at 280 or 320nm, the emission of both compounds is almost not affected by solvent polarity or oxygen presence, showing two bands for I and one for II in the 350-450nm region. Emission of II follows a mono-exponential decay, while I decays following a bi-exponential law, hypothesized from πpyrazine →π*pyrazine and πpyrazol →π*pyrazine transitions. Photodegradation of I and II follows a first-order kinetic with constants of 1.18×10-2 min-1 and 0.13×10-2 min-1 , respectively. Results suggest that photodegradation of I starts with the loose of bromide followed by intermolecular pyrazolyl subtraction and ring opening. This path is not available for II, which is reflected in its enhanced photostability.

4-(4-Bromophenyl)-2-(3-(4-chlorophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)-1,3-thiazole

The asymmetric unit of the title compound, C37H28BrClN8S, comprises one molecule. The molecule consists of two ring systems joined by a C—C bond between the dihydropyrazolyl and pyrazolyl rings of the two extended ring systems. The angles between adjacent ring planes of the tolyl–triazolyl–pyrazolyl–phenyl ring system are 48.2 (1), 12.3 (2) and 22.2 (2)°, respectively, with angles of 19.7 (1), 5.6 (2) and 0.9 (2)° between the rings of the chlorophenyl–thiazolyl–dihydropyrazolyl–bromophenyl set. The pyrazolyl and dihydropyrazolyl rings are inclined at 68.3 (1)° to one another. In the crystal, C—H...Cl interactions form chains of molecules parallel to theb-axis direction.

4-(4-Bromophenyl)-2-(3-(4-bromophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)-1,3-thiazole

In the title compound, C37H28Br2N8S, the dihedral angles between the planes of tolyl–triazolyl–pyrazolyl–phenyl rings are 47.5 (1), 11.4 (2) and 22.4 (2)°, respectively, and the angles between the bromophenyl–thiazolyl–dihydropyrazolyl–bromophenyl rings are 16.0 (2), 5.1 (2) and 0.8 (2)°, respectively. The dihedral angle between the planes of the pyrazolyl and dihydropyrazolyl rings is 67.7 (1)°. In the crystal, weak C—H...Br interactions form chains of molecules propagating in the [010] direction.

(E)-2-Benzoyl-3-[1-phenyl-3-(thiophen-2-yl)-1H-pyrazol-4-yl]acrylonitrile

The asymmetric unit of the title compound, C23H15N3OS, consists of two crystallographically independent molecules, which are related by a pseudo-inversion centre. In one molecule, the pyrazolyl ring makes dihedral angles of 35.7 (4), 19.1 (1) and 47.3 (1)°, respectively, with the thiophenyl ring, the attached phenyl ring and the phenyl ring of the benzoyl group. In the second molecule, the corresponding values are 37.4 (1), 16.1 (1) and 48.2 (1)°, respectively. In the crystal, the two independent molecules are linked to each otherviaa π–π interaction between the pyrazolyl rings [centroid–centroid distance = 3.578 (12) Å]. Weak intermolecular C—H...O interactions are also observed. The thiophenyl ring of one molecule is disordered over two orientations, with a refined occupancy ratio of 0.768 (3):0.232 (3).

4-(4-Bromophenyl)-2-(3-(4-chlorophenyl)-5-{3-[5-methyl-1-(4-methylphenyl)-1H-1,2,3-triazol-4-yl]-1-phenyl-1H-pyrazol-4-yl}-4,5-dihydro-1H-pyrazol-1-yl)thiazole

In the title compound, C37H28BrClN8O, the linked chlorophenyl, pyrazolyl and thiazolyl ringss are almost coplanar, with dihedral angles of 0.6 (3)° between the chlorophenyl and pyrazolyl rings and 5.4 (3)° between the pyrazolyl and thiazolyl rings. The dihedral angle between the thiazolyl and bromophenyl rings is 17.5 (2)°. The central pyrazolyl rings subtend a dihedral angle of 67.7 (1)°. In the crystal, π–π and C—H...Br interactions link the molecules to form columns parallel to [010]. The π–π interactions involve partially overlapping nonparallel bromophenyl and tolyl groups.

Multiple coordination modes of a new ditopic bis(pyrazolyl)methane-based ligand

A new ditopic ligand, N-(2,2-bis(pyrazolyl)ethyl)-2,2-bis(pyrazolyl)acetamide ((pz)2CH-C(O)-NH-CH2-CH(pz)2, L4Pz, pz = pyrazolyl ring), comprising two bis(pyrazolyl)methane donor groups linked via an amide bridge, has been prepared from the reaction of HOOCCH(pz)2 and H2NCH2CH(pz)2. The ligand coordinates to various metallic salts (i.e. AgO3SCF3, PdCl2, Re(CO)5Br, and Fe(BF4)2), in either a κ2-μ-κ2 or a κ3-μ-κ2 fashion, depending on the coordination preferences of the metallic center. These compounds were characterized by NMR, UV-Vis and IR spectroscopy, and in solid state by single crystal X-ray diffraction. In the case of silver(i), a mono-dimensional coordination polymer was obtained, while the others were found to be discrete complexes. The synthesis and characterization of a heterobimetallic complex is also described. In solid state, all compounds are associated into supramolecular architectures via hydrogen bonding and pyrazolyl embrace interactions.

4-Methoxy-N-(1-methyl-1H-indazol-7-yl)benzenesulfonamide hemihydrate

The asymmetric unit of the title compound, 2C15H15N3O3S·H2O, comprises two crystallographically independent organic molecules and one water molecule, all in general positions. Each organic molecule comprises an indazolyl system linked through a sulfonamide group to a methoxybenzene ring. The most important difference between the two organic molecules is the dihedral angle between the fused-ring system and the methoxybenzene ring, which is 56.32 (7)° in one molecule and 35.35 (8)° in the other. In the crystal, the organic and water molecules are connected into supramolecular chains along thecaxis through O—H...N, O—H...O, N—H...O and N—-H...N hydrogen bonds; in addition, a π–π interaction between pyrazolyl rings [inter-centroid separation = 3.7547 (12) Å] is noted.

Comparison of thallium(I) complexes with mesityl-substituted tris(pyrazolyl)hydroborate ligands, [Tl{HB(3-Ms-5-Mepz)3}] and [Tl{HB(3-Ms-5-Mepz)2(3-Me-5-Mspz)}

Tris(pyrazolyl)borate (scorpionate) ligands can be considered as the most prolific ligands in contemporary coordination chemistry due to the availability of various steric and electronic substituents at the pyrazolyl rings that allow fine-tuning of the open-coordination site for metal centres. The thallium(I) complexes of anionic tridentate-chelating scorpionate ligands, namely [tris(3-mesityl-5-methyl-1H-pyrazol-1-yl-κN2)hydroborato]thallium(I) monohydrate, [Tl(C39H46BN6)]·H2O, (I), and [bis(3-mesityl-5-methyl-1H-pyrazol-1-yl-κN2)(5-mesityl-3-methyl-1H-pyrazol-1-yl-κN2)hydroborato]thallium(I), [Tl(C39H46BN6)], (II), show a {TlIN3} coordination, with average TlI-N bond lengths of 2.53 and 2.55 Å in (I) and (II), respectively. The overall TlI coordination geometry is distorted trigonal pyramidal, with the average N-TlI-N angle being approximately 73° for both. The dihedral angle between the planes of the pyrazolyl and benzene rings of the mesityl group is 82° in (I), while the corresponding angles in (II) are in the range 64-104°. The structural differences between the two ligands are expected to contribute to the different reactivities of the transition metal coordination complexes towards activation of small molecules such as dioxygen and ethylene.

Side-on coordination mode of a pyrazolyl group in the structure of a divalent [Sm{B(3-Mepz)4}2] complex (3-Mepz is 3-methylpyrazol-1-yl).

The discovery of polypyrazolylborate ligands allowed the development of various chemical fields and these ligands are an alternative to cyclopentadienyl, because both ligands have the same charge and donate the same number of electrons, as well as adopting the same facial geometry. Easy control of the bulkiness of polypyrazolylborate ligands is possible by modification of the substituents in the 3- and 5-positions of the pyrazolyl rings. The title complex, bis[tetrakis(3-methyl-1H-pyrazol-1-yl)borato]samarium(II), [Sm(C16H20BN8)2], was synthesized from the reaction of SmI2 with potassium tetrakis(3-methyl-1H-pyrazol-1-yl)borate, denoted K[B(3-Mepz)4], in tetrahydrofuran. The X-ray structure analysis revealed an unusual side-on coordination mode of a 3-methylpyrazolyl group through an N=N group in the B(3-Mepz)4 ligand. The distortion is defined by the B-N-N-Sm torsion angle [85.5 (4)°]. This is in contrast to the structure of the similar divalent samarium complex [Sm(TpMe2 is tris(3,5-dimethylpyrazol-1-yl)borate], which displays normal κ3-bonding modes of the TpMe2 ligands.

An Acetylacetonate or a Pyrazole? Both! 3-(3,5-Dimethyl-pyrazol-4-yl)pentane-2,4-dione as a Ditopic Ligand

The alternative coordination sites of 3-(3,5-dimethyl-pyrazol-4-yl)pentane-2,4-dione (H2acacPz) differ with respect to Pearson hardness. The softer, heterocyclic moiety was used as N donor toward Zn(II) and Ag(I); it yielded a tetrahedral, neutral Zn complex in the former and a monocationic, linear bis(ligand) Ag complex in the latter case. After deprotonation with silver benzoate, the pyrazolyl ring may act as a monoanionic N,N′-bridge between neighboring cations in a hexanuclear Ag aggregate; in addition to ligand-supported Ag···Ag distances of ca. 3.2 A, these aggregates feature ligand-unsupported argentophilic interactions of ca. 2.9 A. With stronger bases and in the presence of oxophilic Mg cations, the harder hydroxyketone part of the H2acacPz ligand may be deprotonated to a chelating acetylacetonate. The resulting bis(ligand) Mg complex has been used as starting compound for a bimetallic derivative: the ditopic ligand allows coordinating cadmium acetate to its dangling N donor site, thus, bridging ...

Organotin(IV) scorpionates – X-ray structure and crystal packing of TpSn(Cl)2(n-Bu) [Tp=hydrotris(pyrazol-1-yl)borate

Abstract Reaction of potassium hydrotris(pyrazol-1-yl)borate (KTp) and n-BuSnCl3 at room temperature led to the quantitative formation of TpSn(Cl)2(n-Bu) (1). Colorless single crystals were obtained from a mixture of toluene/dichloromethane and were characterized as TpSn(Cl)2(n-Bu)·½ toluene. Complex 1 crystallizes in the triclinic P1̅ space group, with Z=2, a=8.0496(8) Å, b=9.4867(9) Å, c=14.2710(14) Å, α=90.365(3)°, β=104.479(3)°, γ=95.066(3)°, and V=1050.60(18) Å3. Its structure exhibits a piano stool conformation involving a distorted octahedral geometry around the central Sn(IV) atom. In the crystal and from a supramolecular point of view, 1 is organized in pairs according to a V-shaped arrangement implicating pyrazolyl rings and through weak intermolecular interactions (π-π, C-H···π, and C-H···Cl). The structural analysis of 1 was completed by infrared and solution NMR spectroscopy measurements as well as elemental analysis, which confirm the X-ray elucidation.

Syntheses of bispyrazolyl monotriazolyl heteroscorpionate platinum(IV) complexes including an unusual Pt-CH2CH2-Pt bridge

Scorpionate ligands provide the benefit of hemilability while minimizing complete dissociation of the ligand. Previous investigations into Tp′PtLnXm complexes [Tp′=hydridotris(3,5-dimethylpyrazolyl)borate] revealed the importance of hemilability as the Tp′ ligand facilitates Pt(II/IV) interconversions. Here we discuss the synthesis and metalation of a series of asymmetric scorpionate ligands bearing two pyrazolyl rings and one triazolyl ring. In addition to utilizing triazole donor arms with differing substituents, we also compare octahedral structures of Pt(IV) complexes with P=O and CH and BH caps at the pole of the facial tridentate umbrella. Oxidation from Pt(II) to Pt(IV) with electrophilic reagents, simple acids and acid chlorides, leads to isomers in some cases, and the binding properties of the various donor arms dictate the stereochemistry of the products. Investigations into the reactivity of heteroscorpionate tridentate ligands bound to platinum(II) led to CCl activation reactions with methylene chloride and 1,2-dichloroethane. Isolation of a dinuclear platinum complex bridged by an ethylene unit produced an unusual proton NMR AA′XX′ pattern in the 1H NMR spectrum due to chirality at each platinum center.