Functionalized bis(pyrazol-1-yl)methanes by organotin halide on the methine carbon atom and their related reactions

The modification of bis(pyrazol-1-yl)methanes by organotin halide on the methine carbon atom has been successfully carried out, and their related reactions have also been studied. Bis(3,5-dimethylpyrazol-1-yl)(iododiphenylstannyl)methane [Ph₂ISnCH(3,5-Me₂Pz)₂] can be obtained by the selective cleavage of the Sn-C_sp² bond in bis(3,5-dimethylpyrazol-1-yl)triphenylstannylmethane with I₂ in a 1:1 molar ratio, while {di(tert-butyl)chlorostannyl}bis(3,5-dimethylpyrazol-1-yl)methane [(t-Bu)₂ClSnCH(3,5-Me₂Pz)₂] and {di(tert-butyl)chlorostannyl}bis(3,4,5-trimethylpyrazol-1-yl)methane [(t-Bu)₂ClSnCH(3,4,5-Me₃Pz)₂] are easily prepared by the reaction of the bis(3,5-dimethylpyrazol-1-yl)methide or bis(3,4,5-trimethylpyrazol-1-yl)methide anion with di(tert-butyl)tin dichloride. The molecular structure of [(t-Bu)₂ClSnCH(3,5-Me₂Pz)₂] determined by X-ray structure analysis indicates that bis(3,5-dimethylpyrazol-1-yl)methide acts as a bidentate monoanionic κ²-[C,N] chelating ligand. Reaction of these bis(pyrazol-1-yl)methanes functionalized by organotin halide with W(CO)₅THF results in the oxidative addition of the relative electrophilic Sn-X (X = Cl or I) bond instead of the Sn-C_sp³ bond to the tungsten(0) atom, yielding new metal-metal bonded complexes R₂SnCHPz₂W(CO)₃X (R = Ph or t-Bu, Pz represents substituted pyrazol-1-yl). Furthermore, treatment of the oxidative addition product (t-Bu)₂SnCH(3,5-Me₂Pz)₂W(CO)₃Cl with n-BuLi results in known complex CH₂(3,5-Me₂Pz)₂W(CO)₄ with the loss of the organotin fragment. In addition, reaction of Ph₂ISnCH(3,5-Me₂Pz)₂ with 2-PySNa (Py = pyridyl) leads to the replacement of iodide by 2-PyS⁻ anion to give Ph₂(2-PyS)SnCH(3,5-Me₂Pz)₂, which subsequently reacts with W(CO)₅THF to result in the decomposition of this ligand, also yielding the known bis(3,5-dimethylpyrazol-1-yl)methane derivative of CH₂(3,5-Me₂Pz)₂W(CO)₄.     

The modification of bis(pyrazol-1-yl)methanes by chalcogen (S and Se) and their related reactions with organotin chloride and M(CO)5THF (M = Mo and W)

The modification of bis(pyrazol-1-yl)methane by sulfur or selenium on the methine carbon has been successfully carried out by the reaction of the bis(pyrazol-1-yl)methide anion, prepared in situ by the reaction of bis(pyrazol-1-yl)methane with n-BuLi, with elemental sulfur or selenium. These bis(pyrazol-1-yl)methylthiolate or selenolate anions reacted with Ph₂SnCl₂ to form new organotin derivatives CH(3,5-Me₂Pz)₂ESnPh₂Cl (Pz = pyrazol-1-yl, E = S (1) or Se (2)), which have been characterized by NMR, IR and elemental analysis. The molecular structure of 2 determined by X-ray structure analysis indicates that bis(3,5-dimethylpyrazol-1-yl)methylselenolate is a bidentate monoanionic κ²-[N,Se] chelating ligand. The treatment of CH(3,5-Me₂Pz)₂ESnPh₂Cl with W(CO)₅THF resulted in the decomposition of ligands to yield pyrazole derivative of (3,5-Me₂PzH)W(CO)₅, while direct treatment of bis(pyrazol-1-yl)methylthiolate or selenolate anions with M(CO)₅THF (M = Mo or W) formed their tricarbonyl metal anions . Succedent reaction of these carbonyl metal anions with Ph₂SnCl₂ or Ph₃SnCl yielded heterobimetalic compounds CH(Pz)₂EM(CO)₃SnPh_nCl_3−n (n = 2 or 3), which have also been characterized by ¹H NMR, IR and elemental analysis. The structure of CH(3,4,5-Me₃Pz)₂SW(CO)₃SnPh₃ (8) has been confirmed by X-ray single crystal diffraction, showing that bis(3,4,5-trimethylpyrazol-1-yl)methylthiolate acts as a tridentate, monoanionic κ³-[N,S,N] chelating ligand.     

New multidentate heteroscorpionate ligands: N-Phenyl-2,2-bis(pyrazol-1-yl)thioacetamide and ethyl 2,2-bis(pyrazol-1-yl)dithioacetate as well as their derivatives

New multidentate heteroscorpionate ligands, N-phenyl-2,2-bis(3,5-dimethylpyrazol-1-yl)thioacetamide PhHNCSCH(3,5-Me₂Pz)₂ (1), N-phenyl-2,2-bis(3,4,5-trimethylpyrazol-1-yl)thioacetamide PhHNCSCH(3,4,5-Me₃Pz)₂ (2), and ethyl 2,2-bis(3,5-dimethylpyrazol-1-yl)dithioacetate EtSCSCH(3,5-Me₂Pz)₂ (8), have been synthesized and their coordination chemistry studied. These heteroscorpionate ligands can act as monodentate, bidentate, or tridentate ligands, depending on the coordinate properties of different metals. Reaction of W(CO)₆ with 1 or 2 under UV irradiation yields monosubstituted carbonyl tungsten complexes W(CO)₅L (L = 1 or 2), in which N-phenyl-2,2-bis(pyrazol-1-yl)thioacetamide acts as a monodentate ligand by the s-coordination to the tungsten atom. In addition, these monosubstituted tungsten complexes have also been obtained by heating ligand 1 or 2 with W(CO)₅THF in THF. While similar reaction of Fe(CO)₅ with 1, 2, or 8 under UV irradiation results in tricarbonyl iron complexes PhHNCSCH(3,5-Me₂Pz)₂Fe(CO)₃ (5), PhHNCSCH(3,4,5-Me₃Pz)₂Fe(CO)₃ (6), and EtSCSCH(3,5-Me₂Pz)₂Fe(CO)₃ (9), respectively, in which N-phenyl-2,2-bis(pyrazol-1-yl)thioacetamide or ethyl 2,2-bis(pyrazol-1-yl)dithioacetate acts as a bidentate ligand through one pyrazolyl nitrogen atom and the CS π-bond in an η²-C,S fashion side-on bonded to the iron atom to adopt a neutral bidentate κ²-(π,N) coordination mode. Treatment of the lithium salt of 1 with Co(ClO₄)₂ · 6H₂O gives complex [PhNCSCH(3,5-Me₂Pz)₂]₂Co(ClO₄) with the oxidation of cobalt(II) to cobalt(III), in which N-phenyl-2,2-bis(3,5-dimethylpyrazol-1-yl)thioacetamide acts as a tridentate monoanionic κ³-(N,N,S) chelating ligand by two pyrazolyl nitrogen atoms and the sulfur atom of the enolized thiolate anion.     

桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L¹),2-吡啶基双(3,5-二甲基吡唑)甲烷(L²)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L³)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)₅ (L=L¹或L³),LW(CO)₄ (L=L¹,L²或L³)和LW(CO)₃ (L=L¹或L²).核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式.在LW(CO)₅中,当配体为L¹时,其倾向于通过咪唑氮与金属配位,而为L³则倾向于利用吡啶氮与金属作用;在LW(CO)₄中,配体L¹表现为通过咪唑氮和吡唑氮原子配位的[N,N']双齿配体,而L²和L³表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)₃中,L¹和L²起着[N,N,N']三齿螯合配体的作用.     

桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L1),2-吡啶基双(3,5-二甲基吡唑)甲烷(L2)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L3)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)5(L=L1或L3),LW(CO)4(L=L1,L2或L3)和LW(CO)3(L=L1或L2)。核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式。在LW(CO)5中,当配体为L1时,其倾向于通过咪唑氮与金属配位,而为L3则倾向于利用吡啶氮与金属作用;在LW(CO)4中,配体L1表现为通过咪唑氮和吡唑氮原子配位的[N,N′]双齿配体,而L2和L3表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)3中,L1和L2起着[N,N,N′]三齿螯合配体的作用。     

Synthesis and reactivity of a triphenyltin-functionalized 1<Emphasis Type="Italic">H</Emphasis>-(3,5-dimethylpyrazol-1-ylmethyl)-1,2,3-benzotriazole

Treatment of 1H-(3,5-dimethylpyrazol-1-ylmethyl)-1,2,3-benzotriazole [CH₂(3,5-Me₂Pz)(Bt)] with one equivalent of n-BuLi followed by Ph₃SnCl gave a ditin derivative [(Ph₃Sn)₂C(3,5-Me₂Pz)(Bt)]. Use of two equivalents of n-BuLi gave CH₂(3,5-Me₂Pz)(Bt-SnPh₃) together with (Ph₃Sn)₂C(3,5-Me₂Pz)(Bt). Reaction of (Ph₃Sn)₂C(3,5-Me₂Pz)(Bt) with W(CO)₅(THF) gave (Ph₃Sn)₂C(3,5-Me₂Pz)(BtW(CO)₅), while the reaction of CH₂(3,5-Me₂Pz)(Bt-SnPh₃) with W(CO)₅(THF) resulted in the formation of three complexes, namely CH₂(3,5-Me₂Pz)(Bt-SnPh₃)W(CO)₅, CH₂(3,5-Me₂Pz)(Bt-SnPh₃)W(CO)₄ and CH₂(3,5-Me₂Pz)(Bt)W(CO)₄. All of these products have been characterized by physicochemical and spectroscopic methods. In addition, the structures of five of the compounds have been confirmed by X-ray structural analyses, revealing that the functionalized 1H-(3,5-dimethylpyrazol-1-ylmethyl)-1,2,3-benzotriazole has variable coordination modes.     

Ruthenium(II) and palladium(II) complexes with 2,6-(bispyrazol-1-yl)pyridines

Ruthenium(II) and palladium(II) complexes [Ru(DMSO)(L)Cl₂] and [Pd(L)Cl]Cl, where L = 2,6-bis(pyrazol-1-yl)pyridine (bpp) or 2,6-bis(3,5-dimethylpyrazol-1-yl)pyridine (bdmpp) have been synthesized. All complexes were characterized by elemental analysis, IR, ¹H NMR, UV-Vis, and cyclic voltammetry measurements.     

3,3-Bis(3,5-dimethylpyrazol-1-yl)propionic acid: A tripodal N,N,O ligand for manganese and rhenium complexes - Syntheses and structures

The tripodal N,N,O ligands 3,3-bis(3,5-dimethylpyrazol-1-yl)propionic acid (Hbdmpzp) (1) and 3,3-bis(pyrazol-1-yl)propionic acid (Hbpzp) (2) form the “missing link” between the well-known bis(pyrazol-1-yl)acetic acids and related ligands with a longer “carboxylate arm”. To illustrate the reactivity of this ligand, manganese and rhenium complexes bearing the ligand bdmpzp are reported. The complexes are compared to related compounds bearing other tripod ligands such as bis(3,5-dimethylpyrazol-1-yl)acetate (bdmpza) and 3,3-bis(1-methylimidazol-2-yl)propionate (bmip). Spectroscopic and structural data are used as a basis for comparison, as well as DFT calculations. Both ligands 1 and 2 and the complexes fac-[Mn(bdmpzp)(CO)₃] (3) and fac-[Re(bdmpzp)(CO)₃] (4) were characterised by X-ray crystallography.     

Tricarbonyl rhenium complexes of bis(pyrazol-1-yl)methane and bis(3,5-dimethylpyrazol-1-yl)methane – Synthesis,spectroscopic characterization,X-ray structure and DFT calculations

Two novel tricarbonyl rhenium complexes based on the bidentate heterocyclic N–N ligands [bis(pyrazol-1-yl)methane(bpzm) and bis(3,5-dimethylpyrazol-1-yl)methane(bdmpzm)] have been synthesized by heating at reflux [Re(CO)₅Cl] with the appropriate N–N ligand in toluene. The compounds have been characterized by IR and UV–Vis spectroscopy and X-ray analysis. Density functional theory (DFT) and time-dependent (TD) DFT calculations have been carried out for the [Re(CO)₃(bdmpzm)Cl] complex.     

Photoelectron spectra of potassium salts of hydrotris(pyrazol-1-yl)borates: electronic structure of the electron withdrawing scorpionates Tp(CF3)2, Tp*Cl and comparison to Tp* and Tp

The electronic structures of the potassium salts of the homoscorpionates hydrotris(3,5-dimethylpyrazol-1-yl)borate (Tp*, 1), hydrotris(4-chloro-3,5-dimethylpyrazol-1-yl)borate (Tp*^Cl, 2) and hydrotris(3,5-bis(trifluoromethyl)pyrazol-1-yl)borate (Tp^(CF₃)₂, 3) are compared using gas-phase photoelectron spectroscopy and density functional theory (DFT). DFT calculations also are reported for the generic scorpionate potassium (hydrotris(pyrazol-1-yl)borate) (KTp). This is the first such experimental probe of the electronic structure of halogen containing scorpionate ligands and subtle differences in the ionizations from the frontier orbitals in the photoelectron spectra of 1 and 3 are observed that give insight into the influence of substituents upon metal–scorpionate bonding. Distinct assignments of the ionizations from the nitrogen σ-donor orbitals (σ_N) and σ_BH molecular orbitals are possible experimentally by the use of variable (He I and He II) excitation energies. The experimentally observed first ionization energy of 3 is stabilized by ∼2.0 eV relative to 1 due to the strong electron withdrawing effect of the trifluoromethyl groups. The photoelectron spectroscopic studies of NaTp^(CF₃)₂ further confirm the assignments of ionizations from σ_N orbitals for 3 associated with the a and e sets in C₃ symmetry. The X-ray crystal structure of 2 as the (μ-aqua)₃(potassium hydrotris(4-chloro-3,5-dimethylpyrazol-1-yl)borate)₂ dimer is also reported.     

Alkynylcarbyne complexes containing various tri- and bidentate ligands such as cyclopentadienide,tris(pyrazolyl)borate,bis(pyrazolyl)acetate and tmeda: synthesis and spectroscopic properties

The (alkynylcarbyne)tungsten complexes [L₃(CO)₂WCCCR] (3a,b–6a,b) [L₃=hydro[tris(3,5-dimethylpyrazol-1-yl)]borato (Tp′, 3), hydro[tris(pyrazol-1-yl)]borato (Tp, 4), cyclopentadienyl (Cp, 5), bis(3,5-dimethylpyrazol-1-yl)acetato (bdmpza, 6); R=SiMe₃ (a), Ph (b)] were prepared in a stepwise fashion from [W(CO)₆] and Li[CCR], (CF₃CO)₂O and M[L₃] (M=Na, K). The formation of 6a,b was highly selective, only complexes with a trans arrangement of the carboxylate group of bdmpza and the alkynylcarbyne ligand were detected. The reaction of [W(CO)₆] with Li[CCR], C₂O₂Cl₂ and tmeda afforded trans-[Cl(CO)₂(tmeda)WCCCR] (7a,b). The electron-donating potential of the different tripodal ligands L₃ was studied by IR- and ¹³C-NMR spectroscopy and compared to that of the ligand combination Cl/tmeda. The IR data suggest that in these complexes bdmpza is a weaker electron donor than Tp′ and Tp but displays stronger electron-donating abilities than Cp. The structures of 6b and 7b were established by X-ray structural analyses.     

以2-(1-吡唑基甲基)吡啶类化合物为配体的羰基钼、钨衍生物的合成及结构

合成了2-[1-(3-叔丁基)吡唑基甲基]吡啶(CH2(Py)(3-ButPz)),并研究了羰基钼(钨)与该配体及其类似物2-(1-吡唑基甲基)吡啶(CH2(Py)(Pz))和2-[1-(3,5-二甲基)吡唑基甲基]吡啶(CH2(Py)(3,5-Me2Pz))的反应,合成了6个含双齿螯合的2-(1-吡唑基甲基)吡啶类配体的四羰基金属衍生物CH2(Py)(3-ButPz)M(CO)4,CH2(Py)(Pz)M(CO)4和CH2(Py)(3,5-Me2Pz)M(CO)4(M=Mo或W)。当用SnCl4处理CH2(Py)(3,5-Me2Pz)M(CO)4时,Sn-Cl键对金属中心发生氧化加成得到2个杂双核金属有机化合物CH2(Py)(3,5-Me2Pz)M(CO)3(Cl)SnCl3。所有新化合物均通过了红外和核磁的表征,CH2(Py)(3-ButPz)W(CO)4和CH2(Py)(3,5-Me2Pz)W(CO)3(Cl)SnCl3的结构还得到了X-射线单晶衍射的确证。用循环伏安法测定了四羰基金属衍生物的电化学性质。     

Rhodium(I) complexes with pyridazine, 4,6-dimethyl-pyrimidine, 4,6-bis(3,5-dimethylpyrazol-1-yl)pyrimidine, 3,6-bis(3,5-dimethylpyrazol-1-yl)pyridazine and 3-(3,5-dimethylpyrazol-1-yl)-6-chloropyridazine

The synthesis and properties of rhodium(I) complexes of formulae [“RhCl(diolefin)”₂(L)] (or [Rh(Cl(diolefin)(L)]), and [Rh(diolefin)(L)]_n(ClO₄)_n are reported. These complexes react with carbon monoxide to yield the related carbonyl derivatives. Ligands used were pyridazine, 4,6-dimethyl-pyrimidine, 4,6-bis(3,5-dimethylpyrazol-1-yl)pyrimidine, 3,6-bis(3,5-dimethylpyrazol-1-yl)pyridazine and 3-(3,5-dimethyl-pyrazol-1-yl)-6-chloropyridazine. Related iridium(I) and gold(I) compounds are also reported.     

Synthesis,spectroscopic characterization,X-ray structure and DFT calculations of five-coordinated chlorocopper(II) complex with bis(3,5-dimethylpyrazol-1-yl)methane

The reaction of copper dichloride dihydrate and bis(3,5-dimethylpyrazol-1-yl)methane affords [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]Cl · 3H₂O. The compound has been studied by IR, UV–Vis spectroscopy and X-ray crystallography. The electronic structure of the [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]⁺ cation has been calculated with the density functional theory (DFT) method. The spin-allowed doublet–doublet electronic transitions of [Cu{H₂C(3,5-Me₂pz)₂}₂Cl]⁺ have been calculated with the time-dependent DFT method, and the UV–Vis spectrum of the title compound has been discussed on this basis.     

Organotransition-Metal Complexes of Multidentate Ligands 3. The Unexpected Derivatives of Bis(3,5-Dimethylpyrazol-1-YL)Methanetetracarbonylmolybdenlim(0) and-Tungsten(0) Complexes

Thermolysis of (H₂CPz′₂)M(CO)₄ (H₂CPz′₂ = bis(3,5-dimethylpyrazol-1-yl)methane; M=Mo, W) in 1,2-dimethoxyethane did not give the expected 16-electron complexes, (H₂CPz′₂)M(CO)₃, but gave dinuclear compounds, [(H₂CPz′₂)M(CO)₃]₂, probably containing two linear carbonyl bridges and no metal-metal interactions. The dimers reacted with CH₃CN to give mononuclear compounds, (H₂CPz′₂)M(CO)₃(NCCH₃), identical to the substitution products between (H₂CPz′₂)M(CO)₄ and CH₃CN.     

Synthesis and reactivity of bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonylmolybdenum and tungsten X-ray crystal structureof bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonyltungsten

Bis(3,5-dimethylpyrazol-1-yl)ethane tetracarbonylmolybdenum (1a) and tungsten (1b) have been synthesized by the direct reaction of bis(3,5-dimethylpyrazolyl)ethane (bmpze) with M(CO)₆ (M = Mo or W). The molecular structure (1b), determined by x-ray crystallography, showed the seven-membered ring W–N–N–C–C–N–N to be in the boat conformation. Upon treatment with RSnCl3 (R=Ph or Cl) in CH₂Cl₂ at room temperature, complexes (1a) and (1b) gave the seven-coordinate oxidative-addition products [(bmpze)M(CO)₃(SnCl₂R)Cl] [M = Mo, R = Ph, (2a); M = W, R=Ph, (2b); M = Mo, R = Cl, (2c); M = W, R = Cl, (2d)]. When complexes (1b) and (2b) were heated under reflux with 1,2-bis(diphenylphosphino)ethane (dppe), the ligand, bmpze, in these complexes was easily removed. The novel compounds were characterized by ¹H-n.m.r., i.r. and elemental analysis.     

Organotransition-Metal Complexes of Multidentates 2. Synthesis and Allyl Bromination of N,N-Bis(3,5-Dimethylpyrazol-1-YL)Methane Derivatives of the Group VI Metal Carbonyls

N,N-Bis(3,5-dimethylpyrazol-1-yl)methane (H₂CPz'₂) reacts with the hexacarbonyls of chromium, molybdenum, and tungsten to give cis-(H₂CPz'₂)M(CO)₄ derivatives with M=Cr, Mo, W. The direct allyl bromination of these complexes is also investigated and only the molybdenum complex is converted into (H₂CPz'₂)Mo(CO)₂(π-C₃H₃)(Br).     

Platinum(IV) complexes with α,ω-bis(pyrazol-1-yl) alkanediyl and diethyl ether/thioether ligands. Crystal structures of dibromodimethyl[1,2-bis(pyrazol-1-yl)ethane]platinum(IV) and trimethyl-bis[2-(pyrazol-1-yl)ethyl]etherplatinum(IV) tetrafluoroborate

Reactions of the flexible α,ω-bis(pyrazol-1-yl) compounds 1,2-bis(pyrazol-1-yl)ethane (L1), 1,8-bis(pyrazol-1-yl)-n-octane (L2), bis[2-(pyrazol-1-yl)ethyl]ether (L3) and bis[2-(pyrazol-1-yl)ethyl]thioether (L4) with precursor organometallic platinum complexes ([(PtBr₂Me₂)_n], [(PtIMe₃)₄] and [(PtMe₂(cod)]/I₂) are described herein. The spectroscopic characterization of the platinum(IV) products of these reactions [PtBr₂Me₂{pz(CH₂)_mpz}], m = 2 (1) or 8 (2), [PtI₂Me₂{pz(CH₂)₂pz}] (3), [PtMe₃(pzCH₂CH₂OCH₂CH₂pz)][BF₄] (4) and [PtMe₃(pzCH₂CH₂SCH₂CH₂pz)][CF₃SO₃] (5), where ‘pz’ is pyrazol-1-yl, is discussed. Furthermore, solid state structures of 1, a complex with a seven-membered chelate ring, and 4, a complex bearing the neutral κ²N,N′,κO ligand bis[2-(pyrazol-1-yl)ethyl]ether (L3) are reported.     

Mono- and heteroligand iron(II) complexes with tris(3,5-dimethylpyrazol-1-yl)methane

Coordination compounds of iron(II) thiocyanate with tris(3,5-dimethylpyrazol-1-yl)methane (HC(3,5-Me₂Pz)₃), [Fe(HC(3,5-Me₂Pz)₃)₂](NCS)₂] (I) and [Fe(HC(3,5-Me₂Pz)₃)(Рhz)(NCS)₂] · H₂O (II), where Рhz is phthalazine, are synthesized. The complexes are studied by X-ray diffraction analysis, diffuse reflectance and IR spectroscopy, and static magnetic susceptibility measurements. The single crystals are obtained, and the molecular and crystal structures of complex II and compounds [Fe(HC(3,5-Me₂Pz)₃)(3,5-Me₂Pz)(NCS)₂] · С₂H₅OH (III), where 3,5-Me₂Pz is 3,5-dimethylpyrazole, and [Fe(HC(3,5-Me₂Pz)₃)₂][Fe(HC(3,5-Me₂Pz)₃)(NCS)₃]₂ (IV) are determined (CIF files CCDC 1415452 (II), 1415453 (III), and 1415454 (IV)). The study of the temperature dependence μ_eff(Т) in a range of 2–300 K shows exchange interactions of the antiferromagnetic character between the iron(II) ions in complexes I and II.     

Spin crossover in homo- and heteroligand iron(II) complexes with tris(pyrazol-1-yl)methane derivatives

The studies concerning coordination compounds of various salts of iron(II) with tris(pyrazol-1-yl)methane derivatives (HC(pz)₃) are discussed. The results of a number of studies on the synthesis and investigation of the homo- and heteroligand iron(II) complexes with tris(3,5- dimethylpyrazol-1-yl)methane (HC(3,5-Me₂pz)₃) are considered. The study of the temperature dependence μ_eff (T) showed that the spin crossover (SCO) ¹A₁?⁵T₂ observed in a series of the compounds discussed is accompanied by thermochromism (color change pink (purple) ? colorless). Specific features of the SCO and their dependence on the outer-sphere anion in the iron(II) complexes are discussed. The data of the recently published work devoted to the synthesis of the iron(II) complexes with three N-substituted HC(pz)₃ derivatives (general formula ^xL, where x = H, CH₂C₆H₅ (Bn) and p-SO₃C₆H₄CH₃ (Ts)) are considered.