A 3D MOF based on Adamantoid Tetracopper(II) and Aminophosphine Oxide Cages: Structural Features and Magnetic and Catalytic Properties

Ewelina I. Sliwa, Dmytro S. Nesterov, Marina V. Kirillova, Julia K ł ak, Alexander M. Kirillov,*

Article

A 3D MOF based on Adamantoid Tetracopper(II) and

Aminophosphine Oxide Cages: Structural Features and Magnetic

and Catalytic Properties

and Piotr Smolenski *

Cite This: Inorg. Chem. 2021, 60, 9631 −9644

Read Online

ACCESS

Metrics & More

Article Recommendations

sı Supporting Information

ABSTRACT: This work describes an unexpected generation of a

new 3D metal−organic framework (MOF), [Cu (μ-Cl) (μ -

O)Cu(OH) (μ-PTAO) ] ·2nCl-EtOH·2.5nH O, from copper-

4 n

(

II) chloride and 1,3,5-triaza-7-phosphaadamantane 7-oxide

PTAO). The obtained product is composed of diamandoid

tetracopper(II) [Cu (μ-Cl) (μ -O)] cages and monocopper(II)

[

Cu(OH) ] units that are assembled, via the diamandoid μ-PTA

O linkers, into an intricate 3D net with an nbo topology. Magnetic

susceptibility measurements on this MOF in the temperature range

−

of 1.8−300 K reveal a ferromagnetic interaction (J = +20 cm ) between the neighboring copper(II) ions. Single-point DFT

calculations disclose a strong delocalization of the spin density over the tetranuclear unit. The magnitude of exchange coupling,

predicted from the broken-symmetry DFT studies, is in good agreement with the experimental data. This copper(II) compound also

acts as an active catalyst for the mild oxidation and carboxylation of alkanes. The present study provides a unique example of an

MOF that is assembled from two diﬀerent types of adamantoid Cu and PTAO cages, thus contributing to widening a diversity of

functional metal−organic frameworks.

INTRODUCTION

realizing multiple N,P- or N,O-coordination modes of PTA or

■

8−20

PTAO cages, respectively.

Therefore, the use of PTA

Over the last decades, the synthesis of metal−organic

frameworks (MOFs) has seen a tremendous development

O as a water-soluble and stable building block oﬀers a

prospective way toward the preparation of novel and

structurally unique metal−organic architectures.

with fascinating applications in catalysis,

magnetism,

biochemistry, and materials science. Among diﬀerent

transition-metal compounds, copper-based MOFs are partic-

ularly attractive, given the recognized signiﬁcance of copper in

Following our research lines on the exploration of PTA and

its derivatives in the design of new metal−organic

8−22

architectures

ties,

and investigation of their functional proper-

molecular magnetism and catalysis and its presence in the

3−28

we report herein the synthesis, reaction intermediate,

active centers of diﬀerent oxidation enzymes. Hence, a good

number of diﬀerent bioinspired copper coordination com-

full characterization, structural and topological features, DFT

calculations, as well as the magnetic and catalytic properties of

a new 3D copper(II) MOF, [Cu (μ-Cl) (μ -O)Cu(OH) (μ-

pounds have been designed and applied in diverse catalytic

−11

transformations,

alization of alkanes (very abundant but inert hydrocarbons).

Cu-based MOFs with intriguing magnetic properties and

which also include the oxidative function-

7,11

PTAO) ] ·2nCl-EtOH·2.5nH O (2).

,12−14

related applications have also been reported.

RESULTS AND DISCUSSION

■

(

To build new MOFs with unique structures and functional

properties, the selection of appropriate organic linkers is

important. Among a variety of organic linkers applied in MOF

research, the cagelike aminophosphine 1,3,5-triaza-7-phosphaa-

damantane (PTA) and its P-oxide (1,3,5-triaza-7-phosphaada-

mantane 7-oxide, PTAO) are very interesting building

blocks that feature a diamondoid geometry and several N,P- or

Synthesis. The compound [Cu (μ-Cl) (μ -O)Cu-

OH) (μ-PTAO) ] ·2nCl-EtOH·2.5nH O (2) was initially

4 n

obtained by a facile self-assembly reaction between copper(II)

Received: March 22, 2021

Published: June 13, 2021

15−17

N,O-sites for coordination.

Nevertheless, despite their

considerable use in aqueous organometallic chemistry, PTA

and PTAO are underexplored as building blocks for the

5−17

design of MOFs.

This might be explained by a diﬃculty in

2021 The Authors. Published by

American Chemical Society

631

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Article

Scheme 1. Simpliﬁed Synthetic Procedures of Compounds 1 and 2

nitrate and PTAO in 2-chloroethanol/ethanol (v/v, 1/1)

route 1, Scheme 1). It was isolated as a red air-stable

(

crystalline solid and then characterized by IR and EPR

spectroscopy, and elemental, thermal, and X-ray diﬀraction

analyses. In addition, in the course of the synthesis of 2, the

formation of the ionic monocopper(II) intermediate [H-

PTAO] [CuCl (NO )] (1) was observed ([H-PTAO] is

a protonated form of PTAO).

This hybrid inorganic−organic compound is considered as a

precursor of 2, formed via a Cu-catalyzed dechlorination of 2-

29−33

chloroethanol (solvent component).

Certainly, the source

of chloride ions in compound 2 is 2-chloroethanol. The use of

this chlorinated solvent is essential for the synthesis of 1 and 2,

as these products are not generated in similar reactions starting

from CuCl and PTAO in ethanol. Surprisingly, a similar

reaction of CuCl and PTAO in methanol instead of an

ethanol/2-chloroethanol mixture leads to an amorphous, ﬁne

red powder of 2′ that has a diﬀerent solvate system (route 2,

Scheme 1). The synthetic protocols for both 2 and 2′ were

optimized, maintaining the same molar copper/PTAO

ratios. Unlike the synthesis of 2′ where methanol was used

as a solvent, the preparation of 2 requires a mixture of ethanol

and 2-chloroethanol.

Figure 1. Powder X-ray patterns for 2 (route 1) and 2′ (route 2).

From the top down: experimental patterns for 2′ (gray) and 2 (black)

and calculated patterns for 2 (red) and 2 after removal of solvent

molecules (orange). The high-angle reﬂections for 2 (black and red)

are shown in detail.

The presence of diﬀerent solvent molecules in the crystal

lattice does not change the PXRD patterns of the 2 and 2′

samples obtained via routes 1 and 2. In addition, a

diﬀractogram simulated for 2 from single-crystal X-ray data

and after removal of solvent molecules shows a good match

with the experimental PXRD patterns (Figure 1). For further

studies, crystalline samples of 2 obtained by route 1 were used.

Compound 1 was isolated as an orange crystalline solid and

structurally characterized, revealing an unprecedented type of

the aqueous Cu(II) nitrate or chloride starting materials,

which might be accelerated by the presence of base (PTAO)

and alcohol solvent medium (EtOH for 2; MeOH for 2′).

Such a hydrolysis results in the formation of Cu(OH) and

Cu(μ -O) fragments that are supported by the coordination of

other ligands present in the reaction systems.

−

[

(

CuCl (NO )] anion, as conﬁrmed by a search of the CSD

Structural Description. The hybrid inorganic/organic

structure of the intermediate [H-PTAO] [CuCl (NO )]

(1) is composed of an inorganic copper(II) anion,

Cambridge Structural Database). Interestingly, in both 1

and 2, the copper centers are ﬁve-coordinate and are

−

2−

simultaneously bound by three Cl ligands. The presence of

[CuCl (NO )] , and two organic [H-PTAO] cations

hydroxo and oxo ligands in 2 is associated with hydrolysis of

(Figure 2a). Within the anion, the ﬁve-coordinate Cu1 atom

632

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Article

Figure 2. Fragments of the crystal structure of [H-PTAO] [CuCl (NO )] (1): (a) molecular unit; (b) H-bonded 1D helical chain. H atoms

(except NH) are omitted for clarity. Color code: Cu (green balls), Cl (yellow), N (blue), O (red), P (orange), C (pale gray), H (gray).

features a signiﬁcantly distorted trigonal bipyramidal

−

{

CuCl O } geometry that is ﬁlled by three terminal Cl

3 2

−

ligands and a terminal bidentate NO₃moiety (Cu1−Cl

.227(2)−2.263(2) Å; Cu1−O 1.881(10)−2.322(12) Å). In

addition, the crystal-packing pattern of 1 reveals an assembly of

cations and anions via N−H···O hydrogen bonds (including a

bifurcated one) into a helical 1D H-bonded chain (Figure 2b).

Interestingly, despite the structural simplicity and the common

combination of chloride and nitrate ligands, the present type of

2−

the anion [CuCl (NO )] is unprecedented.

The structure of [Cu (μ-Cl) (μ -O)Cu(OH) (μ-PTA

O) ] ·2nCl-EtOH·2.5nH O (2) discloses a very intricate 3D

metal−organic framework that is driven by the tetracopper(II)

adamantoid-like [Cu (μ-Cl) (μ -O)] secondary building units

(

SBUs), the monocopper(II) [Cu(OH) ] blocks, and the μ-

PTAO linkers (Figure 3). The compound crystallizes in a

cubic crystal system, and its formula unit is composed of four

−

symmetry-quivalent Cu1 atoms, six μ-Cl ligands, one central

2−

μ₄-O moiety, and four equivalent μ-PTAO linkers, in

addition to a second Cu2 center with two terminal OH ligands

and crystallization solvent molecules.

Within the tetracopper(II) [Cu (μ-Cl) (μ -O)] SBU

Figure 3a), the Cu1 atoms are ﬁve-coordinate and adopt a

(

trigonal-bipyramidal {CuCl NO} geometry. It is populated by

−

2−

three μ-Cl ligands (Cu1−Cl 2.390(2) Å), one μ -O ligand

(

Cu1−O 1.9165(8) Å), and a N donor of the μ-PTAO

linker (Cu1−N 2.014(6) Å). The metal centers and ligands

within the Cu SBUs are arranged into a highly symmetric

adamantoid cage with Cu1···Cu1 contacts of ∼3.13 Å. Within

the monocopper(II) [Cu(OH) ] block (Figure 3b), the Cu2

center is six-coordinate and shows an ideal octahedral {CuO₆}

geometry, which is occupied by the four O donors of the μ-

PTAO linkers (Cu2−O 1.935(7) Å) and the two terminal

OH ligands (Cu2−O 2.544(7) Å). The μ-PTAO linkers act

as bidentate N,O-bridging ligands and multiply interconnect

Figure 3. Fragments of the crystal structure of [Cu (μ-Cl) (μ -

the Cu₄SBUs with the [Cu(OH) ] blocks (Cu1···Cu2

O)Cu(OH) (μ-PTAO) ] ·2nCl-EtOH·2.5nH O (2): (a) coordi-

separation 6.718 Å) to generate an intricate 3D metal−organic

nation environment and connectivity of Cu1 centers (green balls)

framework (Figure 3c). Interestingly, both Cu SBUs and μ-

within the tetracopper(II) [Cu (μ-Cl) (μ -O)] cage; (b) coordina-

PTAO linkers feature an adamantoid geometry.

tion environment and connectivity of Cu2 centers (light green) within

To get further insight into the structure of MOF 2, we

carried out its topological analysis by applying the concept of

the monocopper(II) [Cu(OH) ] moiety; (c) 3D metal−organic

framework (view along the a axis). H atoms and solvent molecules are

omitted for clarity. Color code: Cu1 (green balls), Cu2 (light green

balls), Cl (yellow), N (blue), O (red), P (orange), C (pale gray).

an underlying net. After ﬁrst round of simpliﬁcation (Figure

a), all of the bridging ligands were reduced to centroids.

Further simpliﬁcation of this net was performed by treating the

Cu SBUs as 4-connected cluster nodes (Figure 4b). These

nodes, along with the 4-connected Cu2 nodes and the 2-

connected μ-PTAO linkers, form a uninodal 4-connected

framework with an nbo (NbO) topology and point symbol of

(6 .8 ) (Figure 4b).

633

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Figure 5 . The magnetic susceptibility of 2 increases with

Article

the nature of the ground state of 2, we investigated the

variation of the magnetization, M, with respect to the ﬁeld at 2

K. The results are shown in Figure 5 (see inset), where the

molar magnetization M is expressed in μ . The compound

does not reach the saturation in the applied ﬁeld range, and the

magnetization at 5 T is equal to 4.50 μ . The magnetization

data were compared with the sum of the Brillouin function of

ﬁve isolated copper(II) ions. The experimental values for 2 are

slightly greater than that expected for ﬁve independent S = 1/2

systems. These results also conﬁrm the ferromagnetic coupling

between the neighboring copper(II) ions.

Figure 4. Topological simpliﬁcation of the 3D MOF structure of 2:

(

[

a) underlying net showing the connectivity of the 4-connected

The structure of 2 is composed of tetracopper(II) [Cu (μ-

Cu (μ-Cl) (μ -O)] SBUs (Cu1, green balls; Cl, yellow; O, red) and

Cl) (μ -O)] cages and monocopper(II) [Cu(OH) ] units

Cu(OH) ] nodes (Cu2, light green balls) through μ-PTAO

assembled into a 3D metal−organic framework. The Cu1···

linkers (gray sticks); (b) further simpliﬁed uninodal 4-connected net

with a nbo (NbO) topology obtained after treating the [Cu (μ-

Cu1 separations in the {Cu OCl } core are approximately 3.13

Cl) (μ -O)] SBUs as 4-connected cage nodes (centroids of Cu

Å, and the closest Cu···Cu distance between the Cu unit and

SBUs, green balls). Views are along the a axis.

Cu2 atom is 6.718 Å. A signiﬁcantly weaker intermolecular

interaction is expected in comparison to an intramolecular

coupling within tetracopper(II) units. The magnetic suscept-

ibility of 2 was ﬁtted according to eq 1, as the sum of two

independent contributions, namely one due to the tetracopper-

Magnetic Studies. The magnetic properties of 2 were

investigated over the 1.8−300 K temperature range. Plots of

magnetic susceptibility χ and χ T product vs T (χ is the

molar magnetic susceptibility for ﬁve Cu ions) are given in

(

II) blocks (Cu1) (χ_m₍_C_u₄_u_n_i_t₎) and one due to the isolated

copper(II) site Cu2 (χ_m₍_C_u₂_a_t_o_m₎), in addition to a possible

temperature-independent term (χ ), with a typical value for

Nα

−

−1

the copper(II) ion of 60 × 10 cm mol .

^χm ⁼^χ

m(Cu4 unit)

⁺^χm(Cu2 atom) ⁺^χNα

(1)

The magnetic susceptibility per tetracopper(II) unit,

χ_m₍_C_u₄_u_n_i_t₎, derived from the van Vleck formula assuming an

46,47

equal g value for the four copper(II) ions,

is given by eq 2

Nβ g

5 + 3 exp 2u

χ_m₍_C_u₄_u_n_i_t₎

kT 5 + 9 exp 2u + 2 exp 3u

(2)

(3)

u = −J/kT

where J is the intracage exchange parameter. The other

symbols have their usual meaning. The contribution χ_m₍_C_u₂_a_t_o_m₎

is expected to follow a Curie−Weiss model for the S = 1/2

spins (eq 4).

Figure 5. Temperature dependence of experimental χ and χ T (χ

per ﬁve Cu atoms) for 2. The solid line is the calculated curve

derived from eqs 1−5. The inset shows the ﬁeld dependence of the

Nβ g

^χm(Cu2 atom)

S(S + 1)

3kT

(4)

magnetization (M per ﬁve Cu atoms) for 2. The solid line is the

Brillouin function curve for the system of ﬁve uncoupled spins with S

When the possible presence of intermolecular exchange is

1/2 and g = 2.0.

taken into account, eq 1 should be modiﬁed by including a

molecular ﬁeld correction term (zJ’). This yields the eq 5:

cooling, together with a simultaneous systematic increase in

−1

corr

χ T from 1.93 cm K mol (3.93 μ ) at 300 K to 2.62 cm K

2zJ′

−

mol (4.58 μ ) at 1.8 K. Following prior data on Cu

1 −

χ_m

Nβ g

(5)

tetramers with the general formula Cu OX L (X = halogen,

6 4

7−45

L = ligand),

the μ vs T pattern allowed the classiﬁcation

A least-squares ﬁtting of the experimental data leads to the

eff

−

−1

of such compounds into two groups: (i) those that exhibit

following values for 2: J = +20.1(1) cm , zJ′ = 0.04(1) cm ,

1−44

−4

increasing μ_e_f_fwith decreasing temperature

and a

and g = 2.20(2) (R = 8.31 × 10 ). The criterion applied to

determine the best ﬁt was based on the minimization of the

sum of squares of the deviation: R = ∑(χ T − χ T) /

∑(χ T) . The calculated curve for 2 (solid line in Figure 5)

maximum followed by a rapid decrease as the temperature is

lowered further and (ii) those for which μ_e_f_fcontinuously

decreases on lowering the temperature. The increase in χ_mT

exp

calc

exp

(

μ_e_f_f) upon cooling indicates that the interactions between the

matches well the experimental magnetic data in the whole

temperature range. The obtained value of J indicates a

ferromagnetic coupling within the tetracopper(II) cluster in

2. Additionally, the value of zJ′ revealed a very weak magnetic

interaction between tetracopper(II) and monocopper(II)

units, as expected for quite large distances between copper(II)

ions in the crystal lattice.

copper(II) ions are ferromagnetic. The values of the Curie and

Weiss constants determined from the relation χ_m⁻= f(T) over

−1

the 1.8−300 K temperature range are equal to 1.92 cm mol

K and 3.2 K, respectively. The positive value of the Weiss

constant also conﬁrms the occurrence of ferromagnetic

interactions between the copper(II) centers in 2. To conﬁrm

634

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Article

Figure 6. 2D contour maps showing the dependences of the DFT DSM calculated exchange couplings in a {Cu OCl X } fragment (see Table S2

for details) on selected structural parameters, where two Cu atoms are replaced with Zn atoms.

6 4

Previous studies of hydroxo-, alkoxo- and phenoxo-bridged

poorly resolved line at 3200 G that can be attributed to

copper(II) compounds indicate that the nature and the

strength of the overall coupling in such systems can be

inﬂuenced by the Cu···Cu distances and Cu−O−Cu angles.

Generally, the longer the Cu···Cu distance, the weaker the

exchange interaction. When the Cu−O−Cu angle is <97.5°,

ferromagnetic interactions can be expected, whereas for angles

higher than 97.5° the interaction is mostly antiferromagnetic,

monocopper(II) [Cu(OH) ] units (g = 2.08) (Figure S3).

DFT Calculations for Magnetic Properties of 2.

Broken-symmetry DFT calculations were performed to

evaluate the exchange couplings in 2. The calculation

methodology was ﬁrst tested on a series of reported binuclear

copper complexes with a {Cu(μ-Cl)(μ-O)Cu} motif. These

calculations showed a suﬃcient level of matching between

experimental and calculated J values (Table S1 ) for the cases

where the dimeric molecules are sterically isolated and do not

with an increasing magnitude as the angle increases.

Therefore, the ferromagnetic coupling in 2 seems to be

−

surprising at ﬁrst glance because the Cu−O−Cu angle is higher

contain volatile ligands (e.g., CH OH or CH O ). The

than 109° and should cause an antiferromagnetic coupling.

diﬀerence between the experimental and calculated exchange

The structure of 2 reveals that copper(II) ions are additionally

linked by chloride bridges. However, no simple magneto-

structural relationship was established relating the value of the

magnetic exchange constant J to the Cu−Cl−Cu bonding

angle or Cu−Cl or Cu···Cu distances in chloro-bridged

couplings for the cases with μ-OCH could be understood if

one considers alteration of the core structure during the

sample preparation (e.g., grinding). A similar observation was

recently made for a tetranuclear nickel complex, [Ni (μ -

OCH ) (Piv) (CH OH) ] (HPiv = pivalic acid), for which the

copper(II) systems. This may be due to the large variation

in structural features observed, such as a number of distinct

coordination geometries, which involve diﬀerent orbitals in the

exchange pathway. On the basis of the theory of super-

magnetic properties were modeled by DFT calculations by

considering the structure alteration after elimination of

coordinated methanol molecules.

The diamagnetic substitution method (DSM), where certain

exchange and on the behavior of coupling parameters with

paramagnetic sites are replaced with diamagnetic sites (Cu →

bridging angles for some μ-hydroxo-copper(II) compounds,

Zn in our case), was applied to evaluate the magnetic

the smaller Cu−Cl−Cu angle and the shorter Cu−Cu distance

may disclose a ferromagnetic interaction in 2. Although the

Cu−Cl−Cu angles and Cu···Cu distances are the most crucial

geometrical parameters, the coupling constant can also be

modulated by terminal ligands. The presence of N-donor

coupling between the certain Cu pairs in 2. The DSM is

known to correctly estimate the exchange couplings in

9−61

polynuclear clusters,

including very large ones, such as

the Fe₃₄core. The coordination geometry of the {Cu OCl }

core in 2 discloses two slightly diﬀerent Cu···Cu separations of

3.126 and 3.138 Å in a [4 + 2] conﬁguration. Hence, we

attempted to calculate two J constants belonging to these

separations. The {Cu OCl (PTAO) } fragment was used,

41,53

apical ligands may also favor ferromagnetic coupling.

However, slight diﬀerences in structural features and 3D

structure in the case of 2 may also cause some distinction in

the magnetic properties from related complexes involving the

where the copper atoms as well as the atoms of the ﬁrst

coordination sphere were modeled at the def2-TZVPP level

and all other atoms at the def2-SVP level. The results of the

DSM calculations are summarized in Table S2 , where three

reported {Cu OCl } complexes (CSD refcodes CUQFID,

{

Cu OCl } core. Moreover, the sign and magnitude of the J

4 6

value obtained from the magnetic calculations for 2 match the

theoretical results (DFT).

EPR Spectra. The EPR spectra of a solid sample of 2

recorded in the X-band at room temperature and 77 K are

essentially similar and additionally conﬁrm the properties

detected by the direct magnetic measurements (Figure S3 ). In

comparison with the spectrum at 77 K, the signals at 293 K are

much sharper and stronger. The observed EPR spectrum is the

average pattern of four copper(II) centers in the ligand ﬁeld of

63−66

JIWKAB, and WEXYON)

were also used for comparative

purposes. The sign and magnitude of predicted exchange

couplings strongly depend on Cu−O(Cl)−Cu angles (Figure

3,67

6), as was accounted for earlier.

The ferromagnetic

coupling is favored by a smaller Cu−O−Cu angle as well as

a shorter Cu···Cu separation, while a Cu−Cl−Cu angle

appears to have an opposite inﬂuence on the J value (Figure

6). Most of the reported structures with the {Cu OCl } unit

a trigonal-bipyramidal {CuCl NO} symmetry and one in an

4−57

octahedral{CuO } geometry.

transition was detected in a low-ﬁeld part of the spectrum,

which conﬁrms the exchange interaction in the tetracopper(II)

Moreover, the ΔM = 2

reveal a symmetry lower than the ideal T , where the

tetranuclear core shows a slight distortion. To take this fact

[

Cu (μ-Cl) (μ -O)] cage. The spectra of 2 also display a

ⁱⁿ^t^o^a^c^c^o^uⁿ^t^,^w^e^a^t^t^e^m^p^t^e^d^t^o^c^a^l^c^u^l^a^t^e^sⁱ^xⁱⁿ^d^e^p^eⁿ^d^eⁿ^t^JCuCu

635

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

weakly antiferromagnetic (Table S2 and Figure 7 ). Although

Article

exchange integrals for a series of literature complexes bearing a

comparable to that for copper atoms (Table 1 and Figure 7).

{

Cu OCl } core (Table S2).

The interaction between the “isolated” copper site Cu2 and

The eﬀect of pronounced spin delocalization in {Cu OCl X }

6 4

complexes was experimentally conﬁrmed recently by

the closest copper site from the Cu unit was predicted to be

polarized neutron diﬀraction. Thus, the mutual inﬂuence of

the copper shoulders is too high and the DSM model is not

applicable in this case.

The J integrals in a polynuclear complex could be estimated

by knowing the energies of the high-spin (E ) and broken-

symmetry (E ) states, using the approach neglecting the

correction for spin projection, developed by Ruiz. In this

model, E_B_S− E = (2S S + S )J . For Cu ions with S =

S = 1/2 this formula simpliﬁes to E − E = J . The

accuracy of this approach has been conﬁrmed by its successful

use toward modeling of the exchange couplings in polynuclear

73−75

complexes, including large-nuclearity cages.

The exchange

couplings in the system of four interacting spins {1,2,3,4} can

be described by six exchange integrals: J , J , J , J , J , and

13 14 23 24

J₃₄(considering the symmetric exchange only). The reliable

determination of n variables requires n + 1 equations.

Therefore, the system depicted in Figure 8 requires the

calculation of Δ = E − E energy diﬀerences for at least

BSij

seven broken-symmetry ij conﬁgurations (where the numbers i

and j indicate the site(s) with ﬂipped α → β spins).

According to the Ruiz approach, the diﬀerences Δ for the

model depicted in Figure 8 are expressed as

Δ = J + J + J

Δ = J + J + J₂₄

Δ = J + J + J₃₄

Δ = J + J₂₄+ J₃₄

Δ₁₂= J + J + J₂₃+ J₂₄

Δ = J + J + J₂₃+ J₃₄

Figure 7. (a) Isosurface of the DFT-calculated spin density for the

triplet state of {Zn CuOCl (NMe ) (PTAO)Cu(Me PO) (H O) }

^Δ23 = J + J + J ⁺^J34

12 13 24

(6)

with a cutoﬀ value of 0.003 e a . The respective fragment was

obtained by truncating the PTAO ligands in the structure of 2 and

replacing three copper sites with zinc sites. (b) Isosurface of the DFT-

calculated spin density for the quintet state of {Cu OCl (PTAO) } (a

fragment of the structure of 2) with the same cutoﬀ value. The

hydrogen atoms (except those of water ligands) are eliminated for

clarity. Color code: Cu, blue; Zn, gray; Cl, green; O, red; N, light

blue; P, purple; C, brown; H, white.

from which the exchange coupling constants can be derived

J = (Δ + Δ − Δ )/2

J₂₃= (Δ − Δ + Δ )/2

= (Δ − Δ + Δ )/2

= (Δ + Δ − Δ )/2

the closest Cu···Cu distance between the Cu unit and Cu2

atom is 6.718 Å, it is known that the couplings at a comparable

J = (Δ + Δ − Δ )/2

−

distance could be quite strong (up to 35 cm ). In the case of

, the calculations evidence that the superexchange interaction

J₂₄= (Δ + Δ − Δ )/2

(7)

mediated by the PTAO ligand is weak but is not zero (Table

S2).

As the calculation of the complete {Cu OCl (PTAO) }

The predicted magnitudes of exchange couplings using the

DSM model are considerably higher than the experimental

values (Table S2). The explanation of this inconsistency lies in

strong spin delocalization within the {Cu OCl } cluster, which

fragment at the def2-TZVPP level is time-consuming, we

investigated the possibility of using basis sets of reduced

precision, as well as the use of truncated PTA O ligands. The

respective results are summarized in Table S3 . As can be seen,

the nature of the substituent has a strong inﬂuence on the

electron conﬁguration of the whole molecule. The choice of a

basis set was also crucial. We ﬁnally found that the

{Cu OCl (NMe ) } fragment (where the coordinates of N

disables the possibility of a correct determination of the

separate J integrals by DSM. With two copper atoms replaced

with zinc atoms, the main spin density lies on the remaining

copper atoms (Table 1). The spin population on bridging Cl

and O atoms is considerably smaller, as expected for a typical

Cu−X−Cu superexchange. However, the single-point calcu-

lations for a quintet state of {Cu OCl } fragments in various

3 4

and C atoms for NMe groups are from the truncated PTA

O ligands, with generated hydrogen atoms) and def2-TZVP

basis set for all atoms give a Δ energy gap similar to that for

complexes reveal the spin density on a central μ -O atom to be

the {Cu OCl (PTAO) }/def2-SVP/def2-TZVPP combina-

636

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

coupling constant due to the risk of overparameterization,

Article

Table 1. Selected Mulliken Spin Populations for the High-Spin State of {Cu OCl (PTAO) } and Its Derivatives with Two

Copper Atoms Replaced with Zinc Atoms

site

J₁(Cu3 = Zn, Cu4 = Zn)

J₂(Cu2 = Zn, Cu4 = Zn)

full Cu₄

Cu1

Cu2

Cu3

Cu4

0.572068

−0.003191

0.292723

0.116693

0.055162

0.009226

0.055162

0.055163

0.092239

0.092240

0.000563

0.571586

−0.003306

0.571586

−0.003306

0.292543

0.054986

0.055168

0.054986

0.055168

0.117274

0.009254

0.092251

0.000552

0.092251

0.000552

0.576406

0.576405

0.576406

0.576405

0.534758

0.113350

0.113908

0.113350

0.113908

0.098293

0.098292

0.098293

Cl12

Cl23

Cl34

Cl14

Cl13

Cl24

The atom coordinates are obtained from an X-ray analysis: B3LYP/G functional, def2-TZVPP basis set for metal atoms and ﬁrst coordination

environment, def2-SVP set for all other atoms. d(Cu1···Cu2) = 3.138 Å. d(Cu1···Cu3) = 3.126 Å. The numbers mean the copper atoms bridged

by the respective chlorine atom. The numbers indicate the copper atom coordinated by the respective nitrogen atom.

spin delocalization, and its magnetic properties were precisely

ﬁtted with the support of a multifrequency, high-ﬁeld EPR

technique. By using the Ruiz approach, an overall behavior and

exchange model symmetry can be predicted with suﬃcient

precision (Table S4 and Figure 9). Next, we tested the same

strategy on the fully asymmetric complex [Cu OCl (L ) ]

(

CSD refcode CUQFID) bearing a tetranuclear core

resembling that in 2. Although the predicted symmetry and

distribution of the energy levels diﬀer from those determined

experimentally, the bulk magnetic behavior is correctly

reproduced (Figure 9). For 2, all of the exchange interactions

were predicted to be ferromagnetic, with the symmetry very

Figure 8. Schematic representation of the tetranuclear core in 2,

showing the numbering of the J constants.

close to T assumed by the experimental model (Table S4).

The diﬀerence in magnitudes between calculated and

experimental couplings could be due to the simpliﬁed

structural fragment used for the calculations, while the

magnetic exchange it strongly dependent on the nature of

the ligands in apical positions at the copper centers within a

tion in a reasonable computational time. Thus, we used the

above settings for further studies.

The results of the respective calculations for 2 as well as two

tetranuclear complexes in the literature are summarized in

Table S4 . We ﬁrst applied this approach to the tetranuclear

Cu unit (Table S3). Also, the featureless magnetic curve of 2

cubanelike cation in [Cu (NH ) (HL ) ][CdBr ]Br ·3DMF·

3 4

H O (CSD refcode FEVYAH; H L = diethanolamine) with

the S = 2 ground spin state. This compound does not exhibit

(Figure 5) prevents ﬁtting with more than one exchange

Figure 9. Reconstructed μ_e_f_fvs T dependences and energy levels (color scheme for insets: singlet, red; triplet, green; quintet, blue) for the

{

[

Cu OCl (NMe ) } fragment of the structure 2 (left), the [Cu (NH ) (HL ) ] cation in the structure FEVYAH (middle), and the neutral

4 6 3 4 4 3 4 4

Cu OCl (L ) ] complex (CUQFID; right); see Table 4 for details. The magnetically isolated paramagnetic copper site Cu2 in 2 was not

4 6 4

included in the simulation. All of the curves were adjusted by applying g = 2.0. The reported magnetic curve for FEVYAH shows the distinct decay

of the magnetic moment at low temperature due to zero-ﬁeld splitting, not accounted for in the present study.

637

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Article

Table 2. Mild Oxidation of Propane Catalyzed by 2

product yield, %

entry

catalyst amount, μmol

C H , atm

T, °C

time, h

isopropyl alcohol

acetone

n-propanol

propanal

total

TON

2.5

1.25

2.0

3.0

1.9

4.6

5.1

2.9

3.9

2.9

3.0

2.9

2.2

2.6

3.9

2.4

3.1

5.7

7.0

8.5

1.4

1.6

1.0

1.2

0.9

1.9

2.1

1.1

2.1

1.5

1.4

1.2

0.7

0.5

0.3

0.7

0.6

0.5

0.8

0.6

0.4

5.9

7.3

7.0

161

182

170

280

274

9.6

1.25

10.9

10.2

13.8

13.5

6.2

1.25

6.1

Reaction conditions: C H (1−8 atm, 0.7−5.6 mmol), H O (50% aqueous, 5.0 mmol), 2 (1.25−2.5 μmol), CH CN (up to 2.5 mL total reaction

volume), 50 °C in a stainless-steel autoclave (20 mL capacity). Yields are based on propane: (moles of product)/(mole of propane) × 100%.

TON, turnover number: (moles of product)/(mole of catalyst). In the presence of TFA promoter (0.025 mmol).

−

neglecting in this way some possible slight diﬀerences between

the individual coupling constants.

per hour) value of ∼500 h and a total yield of 14.4% after 7

min.

Catalytic Studies. Following our interest in the metal-

We also studied the eﬀect of the catalyst amount on the

catalyzed oxidative functionalization of alkanes under mild

maximum initial reaction rate (W ) and the total product yield

7−79

conditions,

we applied compound 2 as a catalyst for the

in the cyclohexane oxidation catalyzed by 2 (Figure S11).

When the catalyst amount is augmented from 1.25 to 10 μmol,

oxidation and carboxylation of gaseous and liquid alkanes (i.e.,

propane and cyclohexane) to alcohols and ketones or

carboxylic acids.

the W value increases with a nonlinear dependence. This

indicates a reaction order above 1, suggesting that more than

one Cu-containing catalytically active species participates in

the rate-limiting reaction step. The same eﬀect was also

observed when multinuclear Fe-based catalytic systems were

In contrast to numerous Cu-catalyzed systems for alkane

oxidation, the reactions catalyzed by 2 do not require the

77−81

presence of an acid promoter.

The oxidation of an inert

82−84

used for alkane oxidation.

When the catalyst amount in

light alkane such as propane in the presence of 2 leads to a

mixture of isopropyl alcohol, acetone, n-propanol, and

propanal with a total yield of 14% based on C H and a

the reaction solution was lowered from 10 to 1.25 μmol, the

maximum TON grew from 68 to 298.

Compound 2 was also screened as a catalyst for the mild

single-pot carboxylation of cyclohexane or propane to form

cyclohexanecarboxylic acid or a mixture of butyric acids,

respectively (Table 3). The reaction protocols involve the

TON (turnover number; e.g. moles of product per mole of

catalyst) value of up to 280 (Table 2). Isopropyl alcohol and

acetone are the main products due to the more reactive nature

of the secondary C atom of the propane molecule. The best

TONs are observed when higher substrate pressures (loadings)

are used. At a lower propane pressure, there is less substrate

present in the system and thus the overall product yield is

higher, although the TON values are lower (Table 2). The

propane oxidation is rather quick, resulting in the maximum

product yields within a few hours. The product yields observed

after the 24 h reaction time slightly decrease due to partial

overoxidation. The eﬀect of the acid promoter is not signiﬁcant

in the oxidation of propane, leading to comparable yields

Table 3. Cu-Catalyzed Hydrocarboxylation of Alkanes

yield, %

alkane

products

total

31.5

cyclohexane

30.0 (cyclohexanecarboxylic acid, C H COOH)

.2 (cyclohexanone, C H O)

6 10

.3 (cyclohexanol, C H OH)

propane

22.0 (isobutyric acid, (CH ) CHCOOH)

28.2

.2 (n-butyric acid, C H COOH)

3 8

(

Table 2, entries 4 and 5); only a minor improvement was

Reaction conditions: cyclohexane (1 mmol) or propane (1 atm), CO

20 atm), 2 (2.5 μmol), CH CN (4 mL), H O (2 mL), K S O (1.5

observed in the presence of a TFA promoter. The fact that the

catalyst is active without an acid promoter represents a feature

of this system. The activity achieved herein is considerable

when the high inertness of gaseous propane and mild reaction

conditions applied are taken into account.

(

mmol), 3 h, 60 °C, stainless-steel autoclave (20 mL capacity). Yields

are based on alkane: (moles of product)/(mole of cycloalkane) ×

100%. Sum of the yields of all products.

The oxidation of cyclohexane catalyzed by 2 results in ∼15%

treatment of the alkane with CO (carbonyl source), H O

yields (based on C H ) of the products, cyclohexanol and

(hydroxyl source), and K S O (oxidant and radical initiator)

cyclohexanone, already after 10 min of the reaction (Figures

S10 and S11). The presence of 10 equiv (relative to the

catalyst amount) of TFA (triﬂuoroacetic acid, known as an

eﬃcient promoter for Cu-containing catalytic systems) does

not a ﬀ ect either the reaction rate or the total product yield

Figure S10 ). Cyclohexane is transformed to a mixture of

cyclohexanol (main product) and cyclohexanone with a total

yield of 17%. The reaction rate is very high, resulting in a TOF

in an aqueous acetonitrile solution at 60 °C. Thus, the

carboxylation of C H yields 30% of C H COOH, along with

minor amounts of cyclohexanone (1.2%) and cyclohexanol

0.3%) as a result of partial alkane oxidation. Propane is

(

transformed to a mixture of isobutyric (main product) and n-

butyric acids with a total yield of 28% (Table 3). In the present

78,85

work, the activity of 2 in the carboxylation of hydrocarbons

is comparable to those of some other systems reported in our

earlier studies (Table S5 in the Supporting Information).

(

turnover frequency, i.e. moles of products per mole of catalyst

638

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Article

DMF, and 2-chloroethanol, slightly soluble in acetone, 1,4-dioxane,

THF, and MeCN, and insoluble in MeOH, EtOH, dichloromethane,

toluene, and octanol. FT-IR (KBr, cm ): 3413 (m), 2960 (w), 2925

CONCLUSIONS

■

In summary, we synthesized a unique 3D metal−organic

framework which is driven by two diﬀerent types of Cu and

−1

(w), 1630 (vw), 1447 (s), 1413 (m), 1384 (s), 1291 (vs), 1250 (m),

1227 (m), 1158 (vs), 1104 (m), 1085 (m), 1022 (s), 987 (s), 957

(vs), 889 (m), 848 (w), 829 (m), 799 (w), 772 (w), 742 (s), 676 (w),

655 (w), 623(s), 556 (s), 457 (w), 440 (w). Anal. Calcd for

C H Cu N O P Cl ·2ClEtOH·3H O (MW 1488.14): C, 22.60; H,

Cu blocks and μ-PTAO linkers. The present compound

extends a very limited family of MOFs assembled from cagelike

aminophosphine oxide linkers, which are still poorly used for

the design of metal−organic architectures. In addition, an

unusual Cu-catalyzed dechlorination of 2-chloroethanol was

observed upon treatment of copper(II) nitrate and PTAO in

a mixture of 2-chloroethanol/ethanol, allowing the isolation

and full characterization of a new hybrid inorganic/organic

material, [H-PTAO] [CuCl (NO )] (1), which is an

24 50

.47; N, 11.29. Found: C, 22.61; H, 4.33; N, 11.30. TG-DTA for 2

(

N , 5 °C/min): 50−150 °C {−2ClEtOH − 3H O}, Δm (%; 14.49

exptl, 14.45 calcd): >150 °C (dec).

The synthesis of [Cu (μ-Cl) (μ -O)Cu(OH) (μ-PTAO) ] ·

4 n

nH O (2′) was as follows (route 2). To a methanol solution (2

mL) of CuCl ·2H O (85.4 mg, 0.5 mmol) was added a methanol

2 2

intermediate in the synthesis of 2. The structural and

topological features of the obtained compounds and their H-

bonding or metal−organic frameworks were discussed in

detail. Furthermore, the magnetic behavior of MOF 2 was

investigated by diﬀerent methods, including DFT calculations.

Variable-temperature magnetic susceptibility and EPR studies

indicate a ferromagnetic interaction between the neighboring

copper(II) ions in the adamantoid Cu₄unit. Moreover,

compound 2 acts as an eﬃcient catalyst for the oxidation

and hydrocarboxylation of alkanes under mild conditions. The

present work also provides a unique example of a functional

MOF that is assembled from two diﬀerent types of adamantoid

solution (45 mL) of PTAO (182.9 mg, 1 mmol) dropwise. The

reaction mixture was stirred at room temperature for 10 min and then

ﬁltered oﬀ, producing a ﬁne dark red solid of 2′ (33% yield, based

−1

onCuCl ). FT-IR (KBr, cm ): 3429 (s), 2960 (m), 2924 (m), 1643

(

m), 1470 (w), 1447 (m), 1426 (w), 1413 (w), 1293 (vs), 1267 (w),

253 (w), 1228 (m), 1156 (vs), 1106 (m), 1088 (vw), 1023 (s), 988

(

m), 959 (vs), 899 (m), 830 (w), 800 (vw), 773 (w), 744 (m), 678

w), 624 (m), 558 (m), 458 (vw), 440 (vw). Anal. Calcd for

C H Cu N O P Cl ·6H O (MW 1381.16): C, 20.87; H, 4.52.

Found: C, 20.16; H, 4.31. TG-DTA for 2′ (N , 5 °C/min): 50−100

C {−6H O} Δm (%; 7.06 exptl, 7.81 calcd): >150 °C (dec).

Reﬁnement Details for X-ray Analysis and Crystal Data.

Single-crystal data collection was performed on a KUMA Xcalibur

diﬀractometer with a Sapphire CCD detector, equipped with an

Oxford Cryosystems open-ﬂow nitrogen cryostat, using ω scans and

graphite-monochromated Mo Kα (λ = 0.71073 Å) radiation. Cell

reﬁnement, data reduction, analysis, and absorption correction were

carried out with CrysAlis PRO (Rigaku Oxford Diﬀraction, Wrocław,

Cu and PTAO cages.

EXPERIMENTAL SECTION

■

Materials and Methods. All synthetic work was performed in air.

Copper(II) nitrate trihydrate (POCh) and solvents (anhydrous

ethanol, 2-chloroethanol; Sigma-Aldrich) were obtained from

commercial sources. 1,3,5-Triaza-7-phosphaadamantane 7-oxide

Poland) software. The structures were solved by direct methods

with SHELXT-2014/5 and reﬁned with full-matrix least-squares

89,90

techniques on F with SHELXL-2018/3.

The void and diﬀerence

86,87

(

PTAO) was synthesized in accord with literature methods.

electron density maps were generated with Olex2-1.3.0. The nitrate

(N7, O3−O5) and chloride (Cl4) anions in 1 were modeled as being

substitutionally disordered with site occupations of 0.559(11) and

0.441(11), respectively. The structure of 2 contains large voids of

−

The infrared spectra (4000−400 cm ) were recorded on a Bruker

Vertex 70 FT−IR instrument using KBr pellets. Elemental analyses

and thermal analyses were performed using a CHNS Vario EL CUBE

apparatus and a TG-DTA Setaram SETSYS 16/18 instrument

1412 Å occupied by solvent molecules (Figure S1 ). The peaks

(

corundum Al O , 100 μL crucible, N atmosphere, heating rate of

0 °C/min), respectively. Powder X-ray diﬀraction (PXRD) analyses

observed in the diﬀerence Fourier map were modeled as

chloroethanol and water molecules. The bond distances and angles

in the chloroethanol model were restrained to ideal values. The H

atoms of the water molecules were not localized. All other hydrogen

atoms in 1 and 2 were placed at calculated positions and reﬁned using

the riding model with U_i_s_o= 1.2U_e_q.

were performed on a Bruker D8 ADVANCE diﬀractometer using Cu

Kα radiation (λ = 1.5418 Å) ﬁltered with Ni. The diﬀractograms were

recorded with a step size of 2θ = 0.016° over the range 2θ = 5−60°

and ratio 0.5. The calculated pattern was obtained from the single-

crystal XRD data using the MERCURY CSD 3.9 package. In catalytic

studies, gas chromatography (GC) analyses were carried out on an

Agilent Technologies 7820A series gas chromatograph (detector,

ﬂame ionization; carrier gas, He; capillary column, BP20/SGE, 30 m

Crystal data for 1: C H Cl₃_.₄₄CuN₆_.₅₆O₃_.₆₇P₂, M = 568.41, a =

8.6028(6) Å, b = 15.9849(9) Å, c = 15.6635(15) Å, β = 90.774(9)°, V

= 2153.8(3) Å , T = 79.8(6) K, space group P2/c, Z = 4, Mo Kα,

10479 reﬂections measured, 4854 independent reﬂections (R_i_n_t

0.22 mm × 0.25 μm).

0.0746), R1 = 0.0918 (I > 2σ(I) for 2823 reﬂections), wR2 = 0.1876,

GOF = 1.088.

Synthesis and Analytical Data. The compounds [H-PTA

O] [CuCl (NO )] (1) and [Cu (μ-Cl) (μ -O)Cu(OH) (μ-PTA

Crystal data for 2: C H Cl Cu N O₁₁_.₅₀P₄, M = 1479.10, a = b

28 65

O) ] ·2nCl-EtOH·2.5nH O (2) and their single crystals were

= c = 32.7826(3) Å, V = 35231.4(10) Å , T = 79.8(6) K, space group

Fm3c, Z = 24, Mo Kα, 16174 reﬂections measured, 1381 independent

obtained by diﬀusing an ethanol solution (40 mL) of copper(II)

nitrate trihydrate (492.6 mg, 2.0 mmol) on a 2-chloroethanol solution

layer of 1,3,5-triaza-7-phosphaadamantane 7-oxide (710.5 mg, 4.0

mmol) (40 mL) in a tube (route 1). Orange crystals of 1 were found

at the junction of the two solutions after 1 day and could be isolated

and analyzed by X-ray diﬀraction (20% yield, based on copper(II)

nitrate). However, if 1 is not isolated and the tube is kept for 1 week,

there is a transformation of 1 into red crystals of compound 2 (10%

yield, based on the copper(II) nitrate). Data for compound 1 are as

reﬂections (R = 0.1089), R1 = 0.0581 (I > 2σ(I) for 946

int

reﬂections), wR2 = 0.1714, GOF = 1.024.

Crystallographic data for the structures reported in this paper have

been deposited with the Cambridge Crystallographic Data Centre as

CCDC-2064900 (1) and CCDC-2064901 (2).

Magnetic and Electron Paramagnetic Resonance (EPR)

Studies. The magnetic properties were investigated over the

temperature range of 1.8−300 K on a Quantum Design MPMS3

SQUID magnetometer. Solid-state EPR spectra of 2 were recorded on

a Bruker ELEXSYS E500 CW-EPR spectrometer in X-band at 298

and 77 K. The magnetization of powdered sample 2 was measured

over the 1.8−300 K temperature range using a Quantum Design

SQUID-based MPMSXL-5-type magnetometer. The superconducting

magnet was generally operated at a ﬁeld strength ranging from 0 to 5

T. Sample measurements were made at a magnetic ﬁeld of 0.5 T. The

−

follows. FT-IR (KBr, cm ): 3435 (m), 3007 (m), 2962 (m), 2926

(

m), 2852 (w), 2626 (w), 2345 (vw), 1734 (vw), 1635 (vw), 1484

s), 1463 (s), 1384 (s), 1351 (m), 1293 (vs), 1275 (s), 1259 (m),

246 (m), 1212 (s), 1164 (vs), 1108 (s), 1089 (w), 1045 (w), 1028

(

s), 1016 (s), 982 (s), 955 (vs), 938 (m), 916 (w), 900 (w), 822 (s),

87 (m), 763 (m), 737 (w), 660 (w), 606 (m), 552 (m), 452 (vw),

41 (w), 417 (m), 386 (w). Compound 2 is soluble in water, DMSO,

639

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Complete contact information is available at:

Article

SQUID magnetometer was calibrated with a palladium rod sample.

Corrections are based on subtracting the sample-holder signal, and

https://pubs.acs.org/10.1021/acs.inorgchem.1c00868

the χ contribution was estimated from Pascal’s constants.

2,93,94

DFT Calculations. “Broken-symmetry”

carried out by using the B3LYP/G functional

calculations were

with the TZVPP

Notes

94−98

The authors declare no competing ﬁnancial interest.

basis set for the copper atoms and coordination sphere and SVP for all

other atoms (unless stated otherwise), using the ORCA 4.2.1

ACKNOWLEDGMENTS

package with integration grids Grid4. For some cases the chain-

of-spheres RIJCOSX approximation was applied, with the support of

■

This work has been supported by the NCN program (2018/

9/B/ST5/01418), Poland, and the Foundation for Science

100

the auxiliary basis set def2/J. The diamagnetic substitution method

71,101

(

DSM)

centers, which were replaced with Zn . The X-ray atom coordinates of

were used without geometry optimization, unless stated otherwise.

was used to “switch oﬀ” the certain paramagnetic Cu

and Technology (FCT) and Portugal 2020 (projects

CEECIND/03708/2017, PTDC/QUI-QIN/3898/2020, LIS-

BOA-01-0145-FEDER-029697, PTDC/QUI-QIN/29778/

2017, UIDB/00100/2020, and contract IST-ID/086/2018).

This paper has been supported by the RUDN University

Strategic Academic Leadership Program. We thank M. Siczek

for X-ray measurements.

In the respective cases, geometry optimization was performed using

the BP86 functional with the TZVP basis set for the metal and SVP

for all other atoms. The dummy H atoms (used for the generation of

structure fragments) were generated by using the Avogadro 1.2.0

102

program.

The energies of the high-spin and broken-symmetry

states were used to extract the J value in copper dimers, according to

103−106

the formalism J_A_B= −2(E

− E )/(S + S ) .

The

REFERENCES

■

MAGPACK program was used to calculate the magnetic susceptibil-

ities and energy states. The isosurfaces of spin densities were drawn

107

1) (a) Xu, C.; Fang, R.; Luque, R.; Chen, L.; Li, Y. Functional

Metal-Organic Frameworks for Catalytic Applications. Coord. Chem.

Rev. 2019 , 388 , 268 −292. (b) Zhu, L.; Liu, X.-Q.; Jiang, H.-L.; Sun,

L.-B. Metal-Organic Frameworks for Heterogeneous Basic Catalysis.

Chem. Rev. 2017, 117, 8129−8176.

using the VESTA 3.5.2 program.

ASSOCIATED CONTENT

sı Supporting Information

The Supporting Information is available free of charge at

https://pubs.acs.org/doi/10.1021/acs.inorgchem.1c00868.

■

2) (a) Dhakshinamoorthy, A.; Asiri, A. M.; Garcia, H. Metal-

Organic Frameworks as Catalysts for Oxidation Reactions. Chem. -

Eur. J. 2016, 22 , 8012 −8024. (b) Gu, Z. Y.; Park, J.; Raiff, A.; Wei, Z.;

Zhou, H.-C. Metal-Organic Frameworks as Biomimetic Catalysts.

ChemCatChem 2014, 6, 67−75.

Additional experimental, synthetic, and spectroscopic

data, details of the crystal structure studies, additional

ﬁgures and tables as described in the text (PDF)

4) Cai, H.; Huang, Y.-L.; Li, D. Biological Metal-Organic

3) Zadrozny, J. M.; Gallagher, A. T.; Harris, T. D.; Freedman, D. E.

A. A Porous Array of Clock Qubits. J. Am. Chem. Soc. 2017, 139,

089−7094.

Frameworks: Structures, Host-Guest Chemistry and Bio applications.

Accession Codes

CCDC 2064900 −2064901 contain the supplementary crys-

tallographic data for this paper. These data can be obtained

free of charge via www.ccdc.cam.ac.uk/data_request/cif , or by

emailing data_request@ccdc.cam.ac.uk , or by contacting The

Cambridge Crystallographic Data Centre, 12 Union Road,

Cambridge CB2 1EZ, UK; fax: +44 1223 336033.

Coord. Chem. Rev. 2019, 378, 207−221.

(5) (a) Bigdeli, F.; Lollar, C. T.; Morsali, A.; Zhou, H. C. Switching

in Metal-Organic Frameworks. Angew. Chem., Int. Ed. 2020, 59,

652−4669. (b) Schneemann, A.; Bon, V.; Schwedler, I.; Senkovska,

I.; Kaskel, S.; Fischer, R. A. Flexible Metal-Organic Frameworks.

Chem. Soc. Rev. 2014, 43, 6062−6096.

(6) (a) Mukherjee, S.; Mukherjee, P. S. Versatility of Azide in

AUTHOR INFORMATION

Corresponding Authors

■

Serendipitous Assembly of Copper(II) Magnetic Polyclusters. Acc.

Chem. Res. 2013, 46, 2556−2566. (b) Liu, F.-L.; Kozlevcar, B.;

Alexander M. Kirillov − Centro de Química Estrutural and

Departamento de Engenharia Química, Instituto Superior

Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal;

Research Institute of Chemistry, Peoples’ Friendship

University of Russia (RUDN University), Moscow 117198,

Russian Federation; Email: kirillov@tecnico.ulisboa.pt

Strauch, P.; Zhuang, G.-L.; Guo, L.-Y.; Wang, Z.; Sun, D. Robust

Cluster Building Unit: Icosanuclear Heteropolyoxocopperate Tem-

plated by Carbonate. Chem. - Eur. J. 2015, 21, 18847−18854.

(7) Nesterov, D. S.; Nesterova, O. V.; Pombeiro, A. J. L. Homo- and

Heterometallic Polynuclear Transition Metal Catalysts for Alkane C-

H Bonds Oxidative Functionalization: Recent Advances. Coord. Chem.

Rev. 2018, 355, 199−222.

Piotr Smolen

Wroc ł aw, 50-383 Wrocław, Poland; orcid.org/0000-

001-5969-6012 ; Email: piotr.smolenski@

chem.uni.wroc.pl

ski − Faculty of Chemistry, University of

(8) Elwell, C. E.; Gagnon, N. L.; Neisen, B. D.; Dhar, D.; Spaeth, A.

D.; Yee, G. M.; Tolman, W. B. Copper-Oxygen Complexes Revisited:

Structures, Spectroscopy, and Reactivity. Chem. Rev. 2017, 117,

2059−2107.

(9) Luz, I.; Corma, A.; Llabres i Xamena, F. X. Cu-MOFs as Active,

Authors

Selective and Reusable Catalysts for Oxidative C-O Bond Coupling

Reactions by Direct C-H Activation of Formamides, Aldehydes and

Ethers. Catal. Sci. Technol. 2014, 4, 1829−1836.

Ewelina I. Sliwa − Faculty of Chemistry, University of

Wrocław, 50-383 Wrocław, Poland

(10) Bilyachenko, A. N.; Dronova, M. S.; Yalymov, A. I.; Lamaty, F.;

Dmytro S. Nesterov − Centro de Química Estrutural and

Departamento de Engenharia Química, Instituto Superior

Técnico, Universidade de Lisboa, 1049-001 Lisbon,

Portugal; orcid.org/0000-0002-1095-6888

Bantrei, X.; Martinez, J.; Bizet, C.; Shul’pina, L. S.; Korlyukov, A. A.;

Arkhipov, D. E.; Levitsky, M. M.; Shubina, E. S.; Kirillov, A. M.;

Shul ’pin, G. B. Cage-like Copper(II) Silsesquioxanes: Transmetala-

tion Reactions and Structural, Quantum Chemical, and Catalytic

Studies. Chem. - Eur. J. 2015, 21, 8758−8770.

Marina V. Kirillova − Centro de Química Estrutural and

Departamento de Engenharia Química, Instituto Superior

Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal

Julia Kłak − Faculty of Chemistry, University of Wrocław, 50-

(11) (a) Kirillova, M. V.; Kozlov, Y. N.; Shul’pina, L. S.; Lyakin, O.

Y.; Kirillov, A. M.; Talsi, E. P.; Pombeiro, A. J. L.; Shul ’pin, G. B.

Remarkably Fast Oxidation of Alkanes by Hydrogen Peroxide

Catalyzed by a Tetracopper(II) Triethanolaminate Complex:

83 Wrocław, Poland

640

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Promoting Effects of Acid Co-Catalysts and Water, Kinetic and

Article

Mechanistic Features. J. Catal. 2009, 268, 26−38. (b) Kirillov, A. M.;

Kopylovich, M. N.; Kirillova, M. V.; Karabach, E. Y.; Haukka, M.;

Guedes da Silva, M. F. C.; Pombeiro, A. J. L. Mild Peroxidative

Oxidation of Cyclohexane Catalyzed by Mono, Di, Tri, Tetra and

Polynuclear Copper Triethanolamine Complexes. Adv. Synth. Catal.

for Reversible “Turn-On ” Sensing of Aniline. J. Mater. Chem. C 2018,

6, 1670−1678.

(26) Smolenski, P.; Jaros, S. W.; Pettinari, C.; Lupidi, G.; Quassinti,

L.; Bramucci, M.; Vitali, L. A.; Petrelli, D.; Kochel, A.; Kirillov, A. M.

New Water-Soluble Polypyridine Silver(I) Derivatives of 1,3,5-Triaza-

7-Phosphaadamantane (PTA) with Significant Antimicrobial and

Antiproliferative Activities. Dalton Trans. 2013, 42, 6572−6581.

(27) Jaros, S. W.; Guedes da Silva, M. F. C.; Florek, M.; Oliveira, M.

006, 348, 159−174.

12) Ahamad, M. N.; Shahid, M.; Ahmad, M.; Sama, F. Cu(II)

MOFs Based on Bipyridyls: Topology, Magnetism, and Exploring

Sensing Ability Toward Multiple Nitroaromatic Explosives. ACS

Omega 2019, 4, 7738−7749.

C.; Smolenski, P.; Pombeiro, A. J. L.; Kirillov, A. M. Aliphatic

Dicarboxylate Directed Assembly of Silver(I) 1,3,5-Triaza-7-Phos-

phaadamantane Coordination Networks: Topological Versatility and

Antimicrobial Activity. Cryst. Growth Des. 2014, 14, 5408−5417.

(13) Nath, A.; Das, S.; Mukharjee, P.; Nath, R.; Kuznetsov, D.;

Mandal, S. Frustrated Magnetism in Cu(II) Based Metal-Organic

(28) Jaros, S. W.; Król, J.; Baza

A.; Nesterov, D.; Kirillov, A. M.; Smolens

nów, B.; Poradowski, D.; Chrószcz,

ki, P. Antiviral, Antibacterial,

Framework. Inorg. Chim. Acta 2019, 486, 158−161.

(14) Minguez Espallargas, G.; Coronado, E. Magnetic Function-

Antifungal, and Cytotoxic Silver(I) BioMOF Assembled from 1,3,5-

Triaza-7-Phoshaadamantane and Pyromellitic Acid. Molecules 2020,

25, 2119−2132.

alities in MOFs: from the Framework to the Pore. Chem. Soc. Rev.

018, 47, 533−557.

15) Phillips, A. D.; Gonsalvi, L.; Romerosa, A.; Vizza, F.; Peruzzini,

M. Coordination Chemistry of 1,3,5-Triaza-7-Phosphaadamantane

PTA): Transition Metal Complexes and Related Catalytic, Medicinal

and Photoluminescent Applications. Coord. Chem. Rev. 2004, 248,

55−993.

16) Bravo, J.; Bolan

(29) Wang, X.; Liu, M.; Wang, Y.; Fan, H.; Wu, J.; Huang, C.; Hou,

H. Cu(I) Coordination Polymers as the Green Heterogeneous

Catalysts for Direct C-H Bonds Activation of Arylalkanes to Ketones

in Water with Spatial Confinement Effect. Inorg. Chem. 2017, 56,

13329−13336.

o, J.; Gonsalvi, L.; Peruzzini, M. Coordination

(30) Shamir, D.; Elias, I.; Albo, Y.; Meyerstein, D.; Burg, A.

ORMOSIL-Entrapped Copper Complex as Electrocatalyst for the

Heterogeneous De-Chlorination of Alkyl Halides. Inorg. Chim. Acta

2020, 500, 119225−119232.

Chemistry of 1,3,5-Triaza-7-Phosphaadamantane (PTA) and Deriv-

atives. Part II. The Quest for Tailored Ligands, Complexes and

Related Applications. Coord. Chem. Rev. 2010, 254, 555 −607.

(17) Guerriero, A.; Peruzzini, M.; Gonsalvi, L. Coordination

(31) Burg, A.; Meyerstein, D. Chapter 7 - The Chemistry of

Monovalent Copper in Aqueous Solutions. Adv. Inorg. Chem. 2012,

64, 219−261.

Chemistry of 1,3,5-Triaza-7-Phosphatricyclo[3.3.1.1]Decane (PTA)

and Derivatives. Part III. Variations on a Theme: Novel Architectures,

Materials and Applications. Coord. Chem. Rev. 2018, 355, 328−361.

(32) Rusonik, I.; Cohen, H.; Meyerstein, D. Cu(I)(2,5,8,11-

Tetramethyl-2,5,8,11-Tetraazadodecane)+ as a Catalyst for Ullmann ’s

Reaction. Dalton Trans. 2003, 10, 2024−2028.

18) Sliwa, E. I.; Nesterov, D. S.; K ł ak, J.; Jakimowicz, P.; Kirillov, A.

(

M.; Smolenski, P. Unique Copper-Organic Networks Self-Assembled

from 1,3,5-Triaza-7-Phosphaadamantane and its Oxide: Synthesis,

Structural Features, and Magnetic and Catalytic Properties. Cryst.

Growth Des. 2018, 18, 2814−2823.

(33) Navon, N.; Burg, A.; Cohen, H.; Eldik, R. V.; Meyerstein, D.

Ligand Effects on the Reactivity of Cu L Complexes Towards

−

Cl CCO . Eur. J. Inorg. Chem. 2002, 2002, 423−429.

(

19) Jaros, S. W.; Guedes da Silva, M. F. C.; Florek, M.; Smolens

ki,

(34) Groom, C. R.; Bruno, I. J.; Lightfoot, M. P.; Ward, S. C. The

Cambridge Structural Database. Acta Crystallogr., Sect. B: Struct. Sci.,

Cryst. Eng. Mater. 2016, B72, 171−179.

P.; Pombeiro, A. J. L.; Kirillov, A. M. Silver(I) 1,3,5-Triaza-7-

phosphaadamantane Coordination Polymers Driven by Substituted

Glutarate and Malonate Building Blocks: Self-Assembly Synthesis,

Structural Features, and Antimicrobial Properties. Inorg. Chem. 2016,

(35) (a) Jensen, J. Aquatic Chemistry ; Wiley: Hoboken, NJ, 2003.

(b) Paulson, A. J.; Kester, D. R. Copper(II) Ion Hydrolysis in

Aqueous Solution. J. Solution Chem. 1980, 9, 269−277. (c) He, J.; Hu,

P.; Wang, Y.-J.; Tong, M.-L.; Sun, H.; Mao, Z.-W.; Ji, L.-N. Double-

Strand DNA Cleavage by Copper Complexes of 2,2 ′-Dipyridyl with

Guanidinium/Ammonium Pendants. Dalton Trans. 2008, 3207−

3214.

(

5, 5886−5894.

20) Jaros, S. W.; Guedes da Silva, M. F. C.; Król, J.; Oliveira, M. C.;

Smolenski, P.; Pombeiro, A. J. L.; Kirillov, A. M. Bioactive Silver-

Organic Networks Assembled from 1,3,5-Triaza-7-Phosphaadaman-

tane and Flexible Cyclohexanecarboxylate Blocks. Inorg. Chem. 2016,

(

5, 1486−1496.

21) Kirillov, A. M.; Wieczorek, S.; Lis, A.; Guedes da Silva, M. F.

C.; Florek, M.; Król, J.; Staroniewicz, Z.; Smolenski, P.; Pombeiro, A.

(36) Blatov, V. A.; Shevchenko, A. P.; Proserpio, D. M. Applied

Topological Analysis of Crystal Structures with the Program Package

ToposPro. Cryst. Growth Des. 2014 , 14 , 3576 −3586.

J. L. 1,3,5-Triaza-7-Phosphaadamantane-7-Oxide (PTA O): New

Diamondoid Building Block for Design of Three-Dimensional Metal-

Organic Frameworks. Cryst. Growth Des. 2011, 11, 2711−2716.

(37) Bertrand, J. A. Five-Coordinate Complexes. Structure and

Properties of μ -Oxo-Hexa-μ -Chloro-Tetrakis{(Triphenylophosphine

Oxide)Copper(II)}. Inorg. Chem. 1967 , 6 , 495 −498.

(38) Bertrand, J. A.; Kelley, J. A. Five-Coordinate Complexes. II.1

Trigonal Bipyramidal Copper(II) in a Metal Atom Cluster. J. Am.

Chem. Soc. 1966, 88, 4746−4747.

(

22) Kirillov, A. M.; Wieczorek, S.; Guedes da Silva, M. F. C.;

ki, P.; Pombeiro, A. J. L. Crystal Engineering

with 1,3,5-Triaza-7-Phosphaadamantane (PTA): First PTA-Driven

Sokolnicki, J.; Smolens

(

D Metal-Organic Frameworks. CrystEngComm 2011, 13, 6329−

(39) Bertrand, J. A.; Kelley, J. A.; Kirkwood, C. E. Five-Coordinate

Copper(II) in a Cubane-Type Structure. Chem. Commun. 1968,

1329−1331.

333.

23) Kirillov, A. M.; Filipowicz, M.; Guedes da Silva, M. F. C.; K ł ak,

J.; Smolenski, P.; Pombeiro, A. J. L. Unprecedented Mixed-Valence

(40) Barnes, J. A.; Hatfield, W. E. The Low-Temperature Magnetic

Cu(I)/Cu(II) Complex Derived from N-Methyl-1,3,5-Triaza-7-

Phosphaadamantane: Synthesis, Structural Features, and Magnetic

Properties. Organometallics 2012, 31, 7921−7925.

Susceptibility of Tetra-Μ -Methoxy-Tetrakis[Salicylaldehydato-

(Ethanol)Nickel(II)], a Complex with a Positive Exchange Coupling

Constant. Inorg. Chem. 1971, 10, 2355−2357.

ki, P.; K ł ak, J.; Nesterov, D. S.; Kirillov, A. M. Unique

24) Smolens

(41) Lines, M. E.; Ginsberg, A. P.; Martin, R. L.; Sherwood, R. C.

Magnetic Exchange in Transition Metal Complexes. VII. Spin

Coupling in μ ₄ Oxohexa μ Halotetrakis [(Triphenylphosphine

Oxide or Pyridine) Copper(II)]: Evidence for Antisymmetric

Exchange. J. Chem. Phys. 1972, 57, 1−19.

Mixed-Valence Cu(I)/Cu(II) Coordination Polymer with New

Topology of Bitubular 1D Chains Driven by 1,3,5-Triaza-7-

Phosphaadamantane (PTA). Cryst. Growth Des. 2012, 12, 5852−

(

857.

25) Jaros, S. W.; Sokolnicki, J.; Wo ł oszyn, A.; Haukka, M.; Kirillov,

A. M.; Smolenski, P. A Novel 2D Coordination Network Built from

Hexacopper(I)-Iodide Clusters and Cagelike Aminophosphine Blocks

(42) Drake, R. F.; Crawford, H.; Hatfield, W. E. Magnetic Studies on

μ ₄ Oxo Hexa μ Chlorotetrakis [(Pyridine)Copper (II)]. J. Chem. Phys.

1974, 60, 4525−4527.

641

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Tetranuclear Copper Trifluoroacetate Complexes. X-ray Structure

Article

(

43) Dickinson, R. C.; Helm, F. T.; Baker, W. A., Jr; Black, T. D.;

Determination of Three Tetranuclear Quinoline Adducts of Copper-

(II) Trifluoroacetate. J. Am. Chem. Soc. 2009, 131, 10279−10292.

(61) Vignesh, K. R.; Langley, S. K.; Murray, K. S.; Rajaraman, G.

What Controls the Magnetic Exchange Interaction in Mixed and

Watson, W. H., Jr Synthesis, Magnetism, Electron Paramagnetic

Resonance Studies, X-Ray Molecular Structure, and Spectral Proper-

ties of Μ -Oxo-Hexa-μ -Chloro-Tetrakis[(3-Quinuclidinone)Copper-

(44) Dickinson, R. C.; Baker, W. A., Jr; Black, T. D.; Rubins, R. S. A

II)]. Inorg. Chem. 1977, 16, 1530−1537.

Homo Valent Mn Disc Like Clusters? A Theoretical Perspective.

Reexamination of The Magnetic Susceptibility of the Coordination

Chem. - Eur. J. 2015, 21, 2881−2892.

Complex μ Oxohexa μ Chlorotetrakis (Triphenylphosphine Oxide)

(62) Dearle, A. E.; Cutler, D. J.; Fraser, H. W. L.; Sanz, S.; Lee, E.;

Dey, S.; Diaz-Ortega, I. F.; Nichol, G. S.; Nojiri, H.; Evangelisti, M.;

Copper(II), Cu OCl (TPPO) . J. Chem. Phys. 1983, 79, 2609 −2614.

III

(45) Wong, H.; Dieck, H. T.; O ’Connor, C. J.; Sinn, E. Magnetic

Rajaraman, G.; Schnack, J.; Cronin, L.; Brechin, E. K. An [Fe ₃ ₄ ]

Exchange Interactions in Tetranuclear Copper(II) Complexes. Effect

of Ligand Electronegativity. J. Chem. Soc., Dalton Trans. 1980, 786−

Molecular Metal Oxide. Angew. Chem., Int. Ed. 2019, 58, 16903−

16906.

89.

(63) Atria, A. M.; Vega, A.; Contreras, M.; Valenzuela, J.; Spodine,

E. Magnetostructural Characterization of μ -Oxohexa-μ -

47) Colacio, E.; Costes, J.-P.; Kivekas, R.; Laurent, J.-P.; Ruiz, J. A

46) Jotham, R. W.; Keetle, S. F. A. Spin-Exchange in Polynuclear

Systems. Inorg. Chim. Acta 1970, 4, 145−149.

Chlorotetrakis(Imidazole)Copper(II). Inorg. Chem. 1999, 38, 5681−

5685.

Quasi-Tetrahedral Tetracopper Cluster with Syn-Anti Bridging

Carboxylate Groups: Crystal and Molecular Structure and Magnetic

Properties. Inorg. Chem. 1990, 29, 4240−4246.

(64) Keij, F. S.; Haasnoot, J. G.; Oosterling, A. J.; Reedijk, J.;

Oconnor, C. J.; Zhang, J. H.; Spek, A. L. A Pyrazole Ligand Yielding

Both Chloro-Bridged Dinuclear and Tetranuclear Copper(II)

Compounds. The Crystal and Molecular Structure of Bis[μ -Chloro-

Chloro(3,4-Dimethyl-5-Phenylpyrazole) (4,5-Dimethyl-3-

(

48) Kahn, O. Molecular Magnetism; VCH: Weinheim, Germany,

993; pp 103−134.

(

49) For example see: (a) Crawford, V. H.; Richardson, H. W.;

Phenylpyrazole)Copper(II)] and of (μ -Oxo)Hexakis(μ -Chloro)-

Wasson, J. R.; Hodgson, D. J.; Hatfield, W. E. Relation Between the

Singlet-Triplet Splitting and the Copper-Oxygen-Copper Bridge

Angle in Hydroxo-Bridged Copper Dimers. Inorg. Chem. 1976, 15,

Tetrakis(3,4-Dimethyl-5-Phenylpyrazole)Tetracopper(II). Inorg.

Chim. Acta 1991, 181, 185−193.

(65) Boca, R.; Dlhan, L.; Makanova, D.; Mrozinski, J.; Ondrejovic,

G.; Tatarko, M. Magnetic Exchange Coupling in Tetranuclear Copper

2107−2110. (b) Haddad, M. S.; Wilson, S. R.; Hodgson, D. J.;

Hendrickson, D. N. Magnetic Exchange Interactions in Binuclear

Copper(II) Complexes with Only a Single Hydroxo Bridge: the X-ray

Structure of μ -Hydroxo-Tetrakis(2,2 ′-Bipyridine)Dicopper(II) Per-

chlorate. J. Am. Chem. Soc. 1981 , 103 , 384 −391. (c) Ruiz, E.;

Alemany, P.; Alvarez, S.; Cano, J. Toward the Prediction of Magnetic

Coupling in Molecular Systems: Hydroxo- and Alkoxo-Bridged

Cu(II) Binuclear Complexes. J. Am. Chem. Soc. 1997, 119 , 1297 −

Clusters of the Type [Cu (μ -O)Cl Br L ]. Chem. Phys. Lett. 2001,

4 4 6 ‑n n 4

344, 305−309.

(66) Weinberger, P.; Schamschule, R.; Mereiter, K.; Dlhan, L.; Boca,

R.; Linert, W. Halide-Bridged Tetranuclear Copper(II) Complexes:

Structural, Vibrational and Magnetic Properties of (μ -Oxo)-Hexakis-

(μ -Chloro)-Tetrakis [(Morpholine)Copper (II)]. J. Mol. Struct.

1998, 446, 115−126.

1303. (d) Ruiz, E.; Alemany, P.; Alvarez, S.; Cano, J. Structural

(67) Hay, P. J.; Thibeault, J. C.; Hoffmann, R. Orbital Interactions in

Metal Dimer Complexes. J. Am. Chem. Soc. 1975, 97, 4884−4899.

(68) Buvaylo, E. A.; Kokozay, V. N.; Vassilyeva, O. Y.; Skelton, B.

W.; Jezierska, J.; Brunel, L. C.; Ozarowski, A. A Cu-Zn-Cu-Zn

Heterometallomacrocycle Shows Significant Antiferromagnetic Cou-

pling Between Paramagnetic Centres Mediated by Diamagnetic

Metal. Chem. Commun. 2005, 4976−4978.

Modeling and Magneto-Structural Correlations for Hydroxo-Bridged

Copper(II) Binuclear Complexes. Inorg. Chem. 1997, 36, 3683−3688.

(50) Willet, R. D.; Gatteschi, D.; Kahn, O. Magneto-structural

Correlations in Exchange Coupled Systems; D. Reidel: Dordrecht, The

Netherlands, 1985; Vol. 16, pp 389−421.

(

51) Goodenough, J. B. Magnetism and the Chemical Bond;

Interscience: New York, 1963; Vol. 1, pp 75−157.

(69) Zaharko, O.; Mesot, J.; Salguero, L. A.; Valenti, R.; Zbiri, M.;

Johnson, M.; Filinchuk, Y.; Klemke, B.; Kiefer, K.; Mys ’kiv, M.;

Strassle, T.; Mutka, H. Tetrahedra System Cu OCl daca : High-

(52) McGregor, K. T.; Watkins, N. T.; Lewis, D. L.; Drake, R. F.;

Hatfield, W. E. Magnetic properties of Di-μ -Hydroxobis(2,2 ′-

Bipyridyl)Dicopper(II) Nitrate, and the Correlation Between the

Singlet-Triplet Splitting and the Cu-O-Cu Angle in Hydroxo-Bridged

Copper(II) Complexes. Inorg. Nucl. Chem. Lett. 1973, 9, 423−428.

Temperature Manifold of Molecular Configurations Governing Low-

Temperature Properties. Phys. Rev. B: Condens. Matter Mater. Phys.

2008, 77, 224408.

(53) Rodríguez-Fortea, A.; Alemany, P.; Alvarez, S.; Ruiz, E.

(70) Zaharko, O.; Brown, P. J.; Mys ’kiv, M. Spin-Density

Distribution in the Tetragonal Cluster Compound Cu OCl daca .

Exchange Coupling in Halo-Bridged Dinuclear Cu(II) Compounds: A

Density Functional Study. Inorg. Chem. 2002, 41, 3769−3778.

Phys. Rev. B: Condens. Matter Mater. Phys. 2010, 81, 172405.

(

54) Hathaway, B. J. In Comprehensive Coordination Chemistry, 1st

(71) Ruiz, E.; Rodriguez-Fortea, A.; Cano, J.; Alvarez, S.; Alemany,

P. About the Calculation of Exchange Coupling Constants in

Polynuclear Transition Metal Complexes. J. Comput. Chem. 2003,

24, 982−989.

(72) Ruiz, E.; Cano, J.; Alvarez, S.; Alemany, P. Broken Symmetry

Approach to Calculation of Exchange Coupling Constants for

Homobinuclear and Heterobinuclear Transition Metal Complexes.

J. Comput. Chem. 1999, 20, 1391−1400.

ed.; Wilkinson, G., Gillard, R. D., McCleverty, J. A., Eds.; Pergamon

Press: Oxford, U.K., 1987; Vol. 5 , pp 533 −774.

(55) Hathaway, B. J. The Correlation of the Electronic Properties

and Stereochemistry of Mononuclear {CuN ₄ ₋₆ } Chromophores. J.

Chem. Soc., Dalton Trans. 1972, 1196−1199.

(56) Pilbrow, J. R. Transition Ion Electron Paramagnetic Resonance;

Oxford Science Publications: Oxford, U.K., 1990; Vol. 1, pp 57−150.

57) Mabbs, F. E.; Collison, D. Electron Paramagnetic Resonance of d

Transition Metal Compounds; Elsevier Science: Amsterdam, 1992; Vol.

6, pp 955−1000.

58) Rajaraman, G.; Christensen, K. E.; Larsen, F. K.; Timco, G. A.;

(

(73) Gajewska, M. J.; Bienko, A.; Herchel, R.; Haukka, M.;

Jerzykiewicz, M.; Ozarowski, A.; Drabent, K.; Hung, C. H. Iron(III)

Bis(Pyrazol-1-yl)Acetate Based Decanuclear Metallacycles: Synthesis,

Structure, Magnetic Properties and DFT Calculations. Dalton Trans.

2016, 45, 15089−15096.

(

Winpenny, R. E. P. Theoretical Studies on Di- and Tetra-Nuclear Ni

Pivalate Complexes. Chem. Commun. 2005, 3053−3055.

(74) Machata, M.; Nemec, I.; Herchel, R.; Travnicek, Z. An

Octanuclear Schiff-Base Complex with a Na Ni Core: Structure,

(59) Nesterov, D. S.; Jezierska, J.; Nesterova, O. V.; Pombeiro, A. J.

L.; Ozarowski, A. An Unprecedented Octanuclear Copper Core with

C ₃ _i Symmetry and a Paramagnetic Ground State. Chem. Commun.

Magnetism and DFT Calculations. RSC Adv. 2017, 7, 25821−25827.

(75) Das, M.; Herchel, R.; Travnicek, Z.; Bertolasi, V.; Ray, D.

60) Ozarowski, A.; Szymanska, I. B.; Muziol, T.; Jezierska, J. High-

014, 50, 3431−3434.

Field EPR and Magnetic Susceptibility Studies on Binuclear and

Anion Coordination Directed Synthesis Patterns for [Ni ] Aggregates:

Structural Changes for Thiocyanate Coordination and Ligand Arm

Hydrolysis. New J. Chem. 2018, 42, 16717−16728.

642

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

Pombeiro, A. J. L. Mild, Single-Pot Hydrocarboxylation of Gaseous

Article

(

76) Buvaylo, E. A.; Kokozay, V. N.; Vassilyeva, O. Y.; Skelton, B.

and Metal-Promoted Highly Efficient and Mild Conversions. Chem.

Commun. 2009, 2353 −2355. (c) Kirillova, M. V.; Kirillov, A. M.;

Alkanes to Carboxylic Acids in Metal-Free and Copper-Promoted

Aqueous Systems. Chem. - Eur. J. 2010, 16, 9485−9493.

(86) Daigle, D. J.; Pepperman, A. B., Jr; Vail, S. L. Synthesis of a

Monophosphorus Analog of Hexamethylenetetramine. J. Heterocycl.

Chem. 1974, 11, 407−408.

W.; Jezierska, J.; Brunel, L. C.; Ozarowski, A. High-Frequency, High-

Field EPR; Magnetic Susceptibility; and X-ray Studies on a

Ferromagnetic Heterometallic Complex of Diethanolamine (H L),

[

Cu (NH ) (HL) ][CdBr ]Br ·3dmf ·H O. Inorg. Chem. 2005, 44,

(

06−216.

77) Gu, J.-Z.; Wen, M.; Cai, Y.; Shi, Z.; Arol, A. S.; Kirillova, M. V.;

Kirillov, A. M. Metal-Organic Architectures Assembled from Multi-

functional Polycarboxylates: Hydrothermal Self-Assembly, Structures,

and Catalytic Activity in Alkane Oxidation. Inorg. Chem. 2019, 58,

(87) Daigle, D. J.; Decuir, T. J.; Robertson, J. B.; Darensbourg, D. J.

1,3,5 Triaza 7 Phosphatricyclo[3.3.1.1.3.7]Decane and Derivatives.

Inorg. Synth. 2007, 32, 40−45.

78) Kirillov, A. M.; Kirillova, M. V.; Pombeiro, A. J. L. Chapter

403−2412.

(88) CrysAlis PRO; Agilent Technologies Ltd: Yarnton, Oxfordshire,

England, 2014.

One-Homogeneous Multicopper Catalysts for Oxidation and Hydro-

carboxylation of Alkanes. Adv. Inorg. Chem. 2013, 65, 1−31.

(89) Sheldrick, G. M. A Short History of SHELX. Acta Crystallogr.,

Sect. A: Found. Crystallogr. 2008 , A64 , 112 −122.

79) Dias, S. S. P.; Kirillova, M. V.; André, V.; K ł ak, J.; Kirillov, A. M.

New Tricopper(II) Cores Self-Assembled from Aminoalcohol

Biobuffers and Homophthalic Acid: Synthesis, Structural and

Topological Features, Magnetic Properties and Mild Catalytic

Oxidation of Cyclic and Linear C5-C8 alkanes. Inorg. Chem. Front.

(90) Sheldrick, G. M. Crystal Structure Refinement with SHELXL.

Acta Crystallogr., Sect. C: Struct. Chem. 2015, C71, 3−8.

(91) Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A.

K.; Puschmann, H. OLEX2: a Complete Structure Solution,

Refinement and Analysis Program. J. Appl. Crystallogr. 2009, 42,

339−341.

80) Marais, L.; Vosloo, H. C. M.; Swarts, A. J. Homogeneous

015, 2, 525−537.

Oxidative Transformations Mediated by Copper Catalyst Systems.

Coord. Chem. Rev. 2021, 440, 213958.

(92) Bain, G. A.; Berry, J. F. Diamagnetic Corrections and Pascal ’s

Constants. J. Chem. Educ. 2008, 85, 532−536.

(81) (a) Kulakova, A. N.; Bilyachenko, A. N.; Levitsky, M. M.;

(93) Malrieu, P.; Caballol, R.; Calzado, C. J.; de Graaf, C.; Guihery,

N. Magnetic Interactions in Molecules and Highly Correlated

Materials: Physical Content, Analytical Derivation, and Rigorous

Extraction of Magnetic Hamiltonians. Chem. Rev. 2014, 114, 429−

492.

(94) Onofrio, N.; Mouesca, J.-M. Analysis of the Singlet-Triplet

Splitting Computed by the Density Functional Theory-Broken-

Symmetry Method: is it an Exchange Coupling Constant? Inorg.

Chem. 2011, 50, 5577 −5586.

(95) Becke, A. D. Density-Functional Exchange-Energy Approx-

imation with Correct Asymptotic Behavior. Phys. Rev. A: At., Mol.,

Opt. Phys. 1988, 38, 3098 −3100.

Khrustalev, V. N.; Korlyukov, A. A.; Zubavichus, Y. V.; Dorovatovskii,

P. V.; Lamaty, F.; Bantreil, X.; Villemejeanne, B.; Martinez, J.;

Shul’pina, L. S.; Shubina, E. S.; Gutsul, E. I.; Mikhailov, I. A.;

Ikonnikov, N. S.; Tsareva, U. S.; Shul ’pin, G. B. Si10Cu6N4 Cage

Hexacoppersilsesquioxanes Containing N Ligands: Synthesis, Struc-

ture, and High Catalytic Activity in Peroxide Oxidations. Inorg. Chem.

017, 56, 15026−15040. (b) Astakhov, G. S.; Bilyachenko, A. N.;

Levitsky, M. M.; Shul’pina, L. S.; Korlyukov, A. A.; Zubavichus, Y. V.;

Khrustalev, V. N.; Vologzhanina, A. V.; Shubina, E. S.; Dorovatovskii,

P. V.; Shul ’pin, G. B. Coordination Affinity of Cu(II)-Based

Silsesquioxanes toward N,N-Ligands and Associated Skeletal Re-

arrangements: Cage and Ionic Products Exhibiting a High Catalytic

Activity in Oxidation Reactions. Inorg. Chem. 2020, 59, 4536−4545.

(96) Perdew, J. P. Density-Functional Approximation for the

Correlation Energy of the Inhomogeneous Electron Gas. Phys. Rev.

B: Condens. Matter Mater. Phys. 1986 , 33 , 8822 −8824.

(97) Perdew, J. P. Erratum: Density-Functional Approximation for

the Correlation Energy of the Inhomogeneous Electron Gas. Phys.

Rev. B: Condens. Matter Mater. Phys. 1986 , 34 , 7406 −7406.

(98) Kendall, R. A.; Fruchtl, H. A. The Impact of the Resolution of

the Identity Approximate Integral Method on Modern Ab Initio

Algorithm Development. Theor. Chem. Acc. 1997 , 97 , 158 −163.

(99) Neese, F. Software Update: the ORCA Program System,

Version 4.0. Wiley Interdiscip. Rev.: Comput. Mol. Sci. 2018 , 8 , 1 −6.

(100) Weigend, F. Accurate Coulomb-Fitting Basis Sets for H to Rn.

Phys. Chem. Chem. Phys. 2006, 8, 1057−1065.

V.; Jezierska, J.; Ozarowski, A.; Kirillov, A. M.; Kopylovich, M. N.;

Pombeiro, A. J. L. An Unprecedented Heterotrimetallic Fe/Cu/Co

Core for Mild and Highly Efficient Catalytic Oxidation of Cyclo-

alkanes by Hydrogen Peroxide. Chem. Commun. 2006, 4605−4607.

(82) Bilyachenko, A. N.; Levitsky, M. M.; Yalymov, A. I.; Korlyukov,

A. A.; Vologzhanina, A. V.; Kozlov, Y. N.; Shul’pina, L. S.; Nesterov,

D. S.; Pombeiro, A. J. L.; Lamaty, F.; Bantreil, X.; Fetre, A.; Liu, D.;

Martinez, J.; Long, J.; Larionova, J.; Guari, Y.; Trigub, A. L.;

Zubavichus, Y. V.; Golub, I. E.; Filippov, O. A.; Shubina, E. S.;

Shul ’pin, G. B. A Heterometallic (Fe Na ) Cage-Like Silsesquioxane:

Synthesis, Structure, Spin Glass Behavior and High Catalytic Activity.

(101) Comba, P.; Hausberg, S.; Martin, B. Calculation of Exchange

Coupling Constants of Transition Metal Complexes with DFT. J.

Phys. Chem. A 2009, 113, 6751−6755.

RSC Adv. 2016, 6, 48165−48180.

(83) Bilyachenko, A. N.; Levitsky, M. M.; Yalymov, A. I.; Korlyukov,

A. A.; Khrustalev, V. N.; Vologzhanina, A. V.; Shul’pina, L. S.;

Ikonnikov, N. S.; Trigub, A. E.; Dorovatovskii, P. V.; Bantreil, X.;

Lamaty, F.; Long, J.; Larionova, J.; Golub, I. E.; Shubina, E. S.;

Shul ’pin, G. B. Cage-like Fe,Na-Germsesquioxanes: Structure,

Magnetism, and Catalytic Activity. Angew. Chem., Int. Ed. 2016, 55,

(102) Hanwell, M. D.; Curtis, D. E.; Lonie, D. C.; Vandermeersch,

T.; Zurek, E.; Hutchison, G. R. Avogadro: an Advanced Semantic

Chemical Editor, Visualization, and Analysis Platform. J. Cheminf.

2012, 4, 17.

(103) Noodleman, L.; Davidson, E. R. Ligand Spin Polarization and

Antiferromagnetic Coupling in Transition Metal Dimers. Chem. Phys.

1986, 109, 131−143.

(104) Noodleman, L. Valence Bond Description of Antiferromag-

netic Coupling in Transition Metal Dimers. J. Chem. Phys. 1981, 74,

5737−5743.

(

5360−15363.

84) Yalymov, A. I.; Bilyachenko, A. N.; Levitsky, M. M.; Korlyukov,

A. A.; Khrustalev, V. N.; Shul’pina, L. S.; Dorovatovskii, P. V.;

Es’kova, M. A.; Lamaty, F.; Bantreil, X.; Villemejeanne, B.; Martinez,

J.; Shubina, E. S.; Kozlov, Y. N.; Shul ’pin, G. B. High Catalytic

Activity of Heterometallic (Fe Na and Fe Na ) Cage Silsesquioxanes

(105) Ginsberg, A. P. Magnetic Exchange in Transition Metal

Complexes. 12. Calculation of Cluster Exchange Coupling Constants

with the X α -Scattered Wave Method. J. Am. Chem. Soc. 1980, 102,

111−117.

in Oxidations with Peroxides. Catalysts 2017, 7, 101.

(85) (a) Kirillova, M. V.; Kirillov, A. M.; Pombeiro, A. J. L. Metal-

Free and Copper-Promoted Single-Pot Hydrocarboxylation of

Cycloalkanes to Carboxylic Acids in Aqueous Medium. Adv. Synth.

Catal. 2009, 351, 2936−2948. (b) Kirillova, M. V.; Kirillov, A. M.;

(106) Bencini, A.; Gatteschi, D. X α -SW Calculations of the

Electronic Structure and Magnetic Properties of Weakly Coupled

‑

Kuznetsov, M. L.; Silva, J. A. L.; Fraus

J. L. Alkanes to Carboxylic Acids in Aqueous Medium: Metal-Free

to da Silva, J. J. R.; Pombeiro, A.

Transition-Metal Clusters. The [Cu Cl ] Dimers. J. Am. Chem. Soc.

2 6

1986, 108, 5763−5771.

643

Inorg. Chem. 2021, 60, 9631−9644

Inorganic Chemistry

(107) Borras-Almenar, J. J.; Clemente-Juan, J. M.; Coronado, E.;

Article

Tsukerblat, B. S. MAGPACK1 a Package to Calculate the Energy

Levels, Bulk Magnetic Properties, and Inelastic Neutron Scattering

Spectra of High Nuclearity Spin Clusters. J. Comput. Chem. 2001, 22,

108) Momma, K.; Izumi, F. VESTA 3 for Three-Dimensional

85−991.

Visualization of Crystal, Volumetric and Morphology Data. J. Appl.

Crystallogr. 2011, 44, 1272−1276.

644