Variable Combinations of Tridentate Ligands in Pt(η3-X3L)(PL) Derivatives: Comparison
Please note this is a comparison between Version 1 by Peter Mikuš and Version 2 by Lindsay Dong.

There are over fifty examples in which the inner coordination spheres about the Pt(II) atoms of the Pt(η3-X3L)(PL) type are formed by variable combinations of donor atoms of tridentate ligands. Each η3-ligand creates two metallocyclic rings. The complexes based on membered metallocyclic rings can be divided into four groups: 1. 6+6-Membered Metallocyclic Rings, 2. 6+5-Membered Metallocyclic Rings, 3. 5+6-Membered Metallocyclic Rings, and 4. 5+5-Membered Metallocyclic Rings.

  • structure
  • Pt(η3-X3L)(PL)
  • distortion
  • trans-effect

1. 6+6-Membered Metallocyclic Rings

There are only three examples in which a η3-ligand creates such rings (Table 1). In [Pt(η3-C22H11F6N3O2–O1,N1,O2)(PPh3)] (at 173 K) [1][4], the η3-ligand forms a metallocyclic ring of the O1C3N1C3O2 type with common ligating N1 atoms. The values of the chelate L-Pt-L angles are 90.6° (O1-Pt-N1) and 90.2° (N1-Pt-O2). The O1C2NN1C3O2 type with the respective chelate angles of 88.2° (O1-Pt-N1) and 90.0° (N1-Pt-O2) was found in [Pt(η3-C14H10N2O3–O1,N1,O2)(PPh3)] (at 150 K) [2][5]. The remaining L-Pt-L angles open in the following order (mean values): 88.1° (O2-Pt-P) < 89.0° (O1-Pt-P) < 176.0° (N1-Pt-P) < 177.7° (O1-Pt-O2). The monodentate PPh3 displayed square-planar geometry about each Pt(II) atom. The Pt-L bond distance increased in the following order (mean values): 1.995 Å (Pt-O1 trans to O2) < 1.996 Å (Pt-O2) < 2.010 Å (Pt-N1) < 2.254 Å (Pt-P).
Table 1.
Structural data for Pt(η
3
-X
3
)(Y) derivatives.
a
—6+6-membered metallocyclic rings.
Complex Chromophore

Chelate Rings

τ
4 b Pt -L c

(Å)
L-Pt-L c
1
,S
1
)(PPh
3)] toluene [5], [Pt(η
)] toluene [8], [Pt(η
3
-C
9
H
9
N
3
OS–O
1
,N
1
,S
1
)(PPh
3
)] (at 100 K) (
Figure 2) [6], and [Pt(η
) [9], and [Pt(η
3
-C
18
H
16
N
2
OS
2
–O
1
,N
1
,S
1
)(PPh
3)] [4] (
)] [7] (
Table 2
). In each of them, the η
3
-ligand creates six- and five-membered metallocyclic rings with a common ligating N
1
atom of the O
1
C
3
N
1
NCS
1
type. The values of the respective chelate angles (mean values) are 92.3° (O
1
-Pt-N
1
) and 84.6° (N
1
-Pt-S
1
). The remaining L-Pt-L bond angles open in the following order (mean values): 90.7° (O
1
-Pt-P) < 92.4° (S
1
-Pt-P) < 175.8° (N
1
-Pt-P) < 175.9° (O
1
-Pt-S
1
). Interestingly, the mean values of both trans-O
1
-Pt-S
1
and N
1
-Pt-P angles are equal. The Pt-L bond distance increases (mean values) in the following order: 2.028 Å (Pt-O
1
trans to S
1
) < 2.035 Å (Pt-N
1
trans to P) < 2.244 Å (Pt-S
1
) < 2.259 Å (Pt-P).
Figure 2. Structure of [Pt(η3-C9H9N3OS–O1,N1,S1)(PPh3)] [6][9].
Table 2. Structural data for Pt(η3-X3)(Y) derivatives. a—6+5-membered metallocyclic rings.
Complex Chromophore

Chelate Rings

τ
4 b Pt -L c

(Å)

(°)
L-Pt-L Ref.
c

(°) Ref.
[Pt(η3-C22H11F6N3O2-O1,N1,O
[Pt(η32)(PPh3)]

(at 173 K)
-C16H14N2OS2-O1,N1,SPtO1N1O2P (O1C3N1C3O2)

0.032
1)(PPh3)] PtO1N1S1P (O1C3N1NCS1)

0.016O
1 1.994(2)

N
1 2.021(2)

O
2 2.004(2)

P 2.256(2)
O1 1.992

N
1 2.034

S
1 2.245

P 2.258O
1,N1 90.6 d

N
1,O2 90.2 d

O
1,O2 179.0

O
1,P 90.6

O
2,P 87.5

N
1,P 177.0 O1,N1 91.2 d

N
1,S1 85.0 e

O
1,S1 176.0

O
1,P 89.0

S
1,P 93.1

N
1,P 178.1[1][4]
[4][7] [Pt(η3-C14H10N2O3-O1,N1,O2)(PPh3)]

(at 150 K)
PtO1N
[Pt(η3-C16H13N3O3S2-O1,N1,S1)(PPh3)]

(at 200 K)
1O2P (O1C2NN1C3O2)

0.024
PtO1N1S1P (O1C3N1NCS1)

0.018O
1 1.995(2)

N
1 2.000(2)

O
2 1.988(2)

P 2.251(2)
O1 2.001

NO
1,N1 88.2 d

N
1,O2 90.0 d

O
1,O2 176.5

O
1,P 89.0

O
2,P 90.7

N
1,P 175.0 [2][5]
[Pt{η3-C12H24S3-S1,S2,S3}(PPh3)]BF4 PtS1S2S3P (S1C3S2C3S3)

0.035
S1 2.330(2)

S
2 2.339(2)

S
3 2.336(2)

P 2.332(2)
S1,S2 87.1(2) d

S
2,S3 89.5(2) d

S
1,S3 176.3(2)

S
1,P 91.1(2)

S
3,P 92.3(1)

S
2,P 171.0(2) [3][6]
(a) Where more than one chemically equivalent distance or angle is present, the mean value is tabulated. The number in parentheses is the e.s.d. (b) Parameter τ4, degree of distortion. (c) The chemical identity of the coordinated atom/ligand is specific to these columns. (d) Six-membered metallocyclic ring.
For the complex [Pt{η3-C12H24S3-S1,S2,S3}(PPh3)]BF4, the η3-ligand creates a pair of six-membered metallocyclic rings of the S1C3S2C3S3 type (as shown in Figure 1) [3][6]. The values of the chelate angles are 87.1° (S1-Pt-S2) and 89.5° (S2-Pt-S3). The remaining L-Pt-L bond angles open in the following order: 91.1° (S1-Pt-P) < 92.3° (S3-Pt-P) < 171.0° (S2-Pt-P) < 176.3° (S1-Pt-S3). The Pt-L bond distance increases in the following order: 2.330 Å (Pt-S1) < 2.332 Å (Pt-P) < 2.336 Å (Pt-S3) < 2.339 Å (Pt-S2 trans to P). Noticeably, the trans-X1-Pt-X3 bond angles are somewhat bigger than the trans-X2-Pt-P bond angles (Table 1).
Figure 1.
Structure of [Pt{η
3
-C
12
H
24
S
3
-S
1
,S
2
,S
3
}(PPh
3)] [3].

2. 6+5-Membered Metallocyclic Rings

There are five examples namely [Pt(η
)] [6].

2. 6+5-Membered Metallocyclic Rings

There are five examples namely [Pt(η
3
-C
16
H
14
N
2
OS
2
–O
1
,N
1
,S
1
)(PPh
3)] [4], [Pt(η
)] [7], [Pt(η
3
-C
16
H
13
N
3
O
3
S
2
–O
1
,N
1
,S
1
)(PPh
3)] (at 200K) [4], [Pt(η
)] (at 200K) [7], [Pt(η
3
-C
8
H
8
N
3
OS–O
1
,N
1
2.041


S1 2.239

P 2.248
O1,N1 92.6 d

N
1,S1 85.3 e

O
1,S1 177.6

O
1,P 89.0

S
1,P 93.3

N
1,P 176.0 [4][7]
[Pt(η3-C8H8N3OS-O1,N1,S1)(PPh3)].toluene PtO1N1S1P (O1C3N1NCS1)

0.020
O1 2.015

N
1 2.031

S
1 2.234

P 2.257
O1,N1 93.1 d

N
1,S1 83.8 e

O
1,S1 176.6

O
1,P 89.9

S
1,P 93.3

N
1,P 176.3 [5][8]
[Pt(η3-C9H9N3OS-O1,N1,S1)(PPh3)]

(at 103 K)
PtO1N1S1P (O1C3N1NCS1)

0.024
O1 2.085

N
1 2.036

S
1 2.257

P 2.260
O1,N1 92.5 d


S1,P 91.2

N
1,P 173.1 [4][7]
(a) Where more than one chemically equivalent distance or angle is present, the mean value is tabulated. The number in parentheses is the e.s.d. (b) Parameter τ4, degree of distortion. (c) The chemical identity of the coordinated atom/ligand is specific to these columns. (d) Six-membered metallocyclic ring. (e) Five-membered metallocyclic ring.

3. 5+6-Membered Metallocyclic Rings

There are four complexes mentioned in this section, namely [Pt(η
3
-C
12
H
10
N
4
–N
1
,N
2
,N
3
)(PPh
3)] (at 100 K) [7], [Pt(η
)] (at 100 K) [10], [Pt(η
3
-C
13
H
9
NO
2
–O
1
,N
1
,O
2
)(PPh
3)] [8], [Pt(η
)] [11], [Pt(η
3
-C
12
H
16
N
2
O
4
Se
2
–Se
1
,N
1
,Se
2
){P(η
1
-C
11
H
19
O
5
)(Ph)
2}] [9], and [Pt(η
}] [12], and [Pt(η
3
-C
29
H
20
F
6
S
2
O–S
1
,S
2
,O
1
)(PPh
3)] (at 100 K) [10], and their structural parameters are gathered in
)] (at 100 K) [13], and their structural parameters are gathered in
Table 3
. The structure of [Pt(η
3
-C
12
H
10
N
4
–N
1
,N
2
,N
3
)(PPh
3)] [7] is shown in
)] [10] is shown in
Figure 3
as an example. Each η
3
-ligand creates five and six metallocyclic rings. The donor atoms of the respective η
3
-ligands play a role in the size of the L-Pt-L chelate angles. These angles increase in the following sequences:
Figure 3. Structure of [Pt(η3-C12H10N4–N1,N2,N3)(PPh3)] [7][10].
Table 3. Structural data for Pt(η3-X3)(Y) derivatives. a—5+6-membered metallocyclic rings.
Complex Chromophore

Chelate Rings

τ
4 b Pt -L c

(Å)
L-Pt-L c

(°)
Ref.
[Pt(η3-C12H10N4-N1,N2,N3)(PPh3)]

(at 100 K)
Pt N1N2N3P (N1C2N2NC2N3)

0.034
N1 1.984

N
2 2.025

N
3 1.964

P 2.255
N1,N2 81.7 e

N
2,N3 89.6 d

N
1,N3 170.6

N
1,P 93.0

N
3,P 96.3

N
2,P 177.2 [7][10]
[Pt(η3-C13H9NO2-O1,N1,O2)(PPh3)] Pt O1N1O2P (O1C2N1C3O2)

0.034
O1 1.975(9)

N
1 2.064(12)

O
2 1.996(9)

P 2.248
O1,N1 82.4(4) e

N
1,O2 94.8(4) d

O
1,O2 176.4(4)

O
1,P 91.5(3)

O
2,P 91.5(3)

N
1,P 172.4 [8][11]
[Pt(η3-C12H16N2O4Se2-Se1,N1,Se2){P(η1-C11H19O5)(Ph)2}] Pt Se1N1Se2 (Se1C2N1NC2Se2)

0.036
Se1 2.394

N
1 2.078

Se
2 2.349

P 2.259
Se1,N1 83.3 e

N
1,Se2 98.3 d

Se
1,Se3 176.3

Se
1,P 87.2

Se
2,P 90.7

N
1,P 170.9 [9][12]
[Pt(η3-C29H20F6O4S2O-S1,S2,O1)(PPh3)]

(at 100 K)
Pt S1S2O1P (S1C2S2C3O1)

0.059
S1 2.268

S
2 2.277

O
1 2.066

P 2.253

N
1,S1 85.1 e

O
1,S1 175.7

O
1,P 91.5

S
1,P 91.0

N
1,P 175.6 S1,S2 90.2 e

S
1,O1 99.2 d

S
1,O1 169.6

S
1,P 89.2

O
1,P 99.2

S
2[6][9]
P 169.4 [10][13] [Pt(η3-C18H16N2OS2-O1,N1,S1)(PPh3)] PtO1N1S1P (O1C3N1NCS1)

0.037
O1 2.045

N
1 2.029

S
1 2.246

P 2.269
O1,N1 92.3 d

N
1,S1 83.2 e

O
1,S1 173.6

O
1,P 93.1
(a) Where more than one chemically equivalent distance or angle is present, the mean value is tabulated. The number in parentheses is the e.s.d. (b) Parameter τ4, degree of distortion. (c) The chemical identity of the coordinated atom/ligand is specific to these columns. (d) Six-membered metallocyclic ring. (e) Five-membered metallocyclic ring.
N1C2N2NC2N3—81.7° (N1-Pt-N2) and 89.6° (N2-Pt-N3); O1C2N1C3O2—2.4° (O1-Pt-N1) and 94.8° (N1-Pt-O2); Se1C2N1NC2Se2—83.3° (Se1-Pt-N1) and 98.3° (N1-Pt-Se2); S1C2S2C3O1—90.2° (S1-Pt-S2) and 99.2° (S2-Pt-O1). The monodentate PL displayed distorted square-planar geometry about Pt(II) atoms. The Pt-L bond distance to PL increased in the following order: 2.025 Å (Pt-N
2
) < 2.064 Å (Pt-N
1
) < 2.078 Å (Pt-N
1
) < 2.277 Å (Pt-S
2
). The order follows the above-mentioned sentence for the Pt-L (L is a common central ligating atom between five and six-rings).

4. 5+5-Membered Metallocyclic Rings

There are thirty-nine compounds in which each η
3
-ligand creates two five-membered metallocyclic rings. These complexes based on variable combinations of atoms involved in the chelate angles can be divided into twelve groups. The structure of [Pt(η
3
-C
33
H
24
P
2
S
2
–S
1
,C
1
,S
2
)(PPh
3
)].CH
2
Cl
2 [11] is shown in
[14] is shown in
Figure 4
. The η
3
-ligand creates two five-membered metallocyclic rings with a common C
1
atom of the S
1
PCC
1
CPS
2
type with chelate angles of 87.9° (S
1
-Pt-C
1
) and 87.7° (C
1
-Pt-S
2
). This is the only example of this type. The PPh
3
demonstrated distorted square-planar geometry about Pt(II) atoms. The remaining L-Pt-L bond angles open in the following order: 89.7° (S
1
-Pt-P) < 94.2° (S
2
-Pt-P) < 173.8° (S
1
-Pt-S
2
) < 176.9° (C
1
-Pt-P). The Pt-L bond distance increases in the following order: 2.020 Å (Pt-C
1
) < 2.316 Å (Pt-S
2
) < 2.332 Å (Pt-S
1
) < 2.322 Å (Pt-P).
Figure 4. Structure of [Pt(η3-C33H24P2S2–S1,C1,S2)(PPh3)] [11][14].
In another two complexes, namely [Pt(η
3
-C
12
H
12
N
2
Te
3
–Te
1
,Te
2
,Te
3
)(PPh
3
)].C
6
H
6
and [Pt(η
3
-C
10
H
8
N
2
Te
3
–Te
1
,Te
2
,Te
3
)(PPh
3)] [12], which are isostructural, the η
)] [15], which are isostructural, the η
3
-ligand creates a pair of five-membered metallocyclic rings with common central ligating Te
2
atoms of the Te
1
CNTe
2
NCTe
3
type. The mean values of the respective angles are 92.2 (±6)° (Te
1
-Pt-Te
2
) and 92.0 (±6)° (Te
2
-Pt-Te
3
). The PPh
3
ligand demonstrated distorted square-planar geometry about each Pt(II) atom. The remaining L-Pt-L bond angles open in the following order (mean values): 88.1 (±1.2)° (Te
3
-Pt-P) ~ 88.1 (±2.31)° (Te
1
-Pt-P) < 173.3 (±8)° (Te
1
-Pt-Te
3
) < 173.4 (±2.1)° (Te
2
-Pt-P). The Pt-L bond distance increases in the following order (mean values): 2.283 (±1) Å (Pt-P) < 2.571 (±2) Å (Pt-Te
2
) < 2.591 (±3) Å (Pt-Te
1
) < 2.592 (±20) Å (Pt-Te
3
).
In another two complexes, namely Pt(η
3
-C
12
H
9
N
2
S
2
B–S
1
,B
1
,S
2
)(PPh
3
)].0.06CH
2
Cl
2 [13] and Pt(η
[16] and Pt(η
3
-C
13
H
14
N
5
S
3
B–S
1
,B
1
,S
2
)(PPh
3)] [14], each η
)] [17], each η
3
-ligand creates a pair of five-membered metallocyclic rings with a common central ligating B
1
atom of the S
1
CNB
1
NCS
2
type. The values of the respective chelate angles are (mean values): 80.4 (±6)° (S
1
-Pt-B
1
) and 85.7 (±8)° (B
1
-Pt-S
2
). The PPh
3
demonstrated distorted square-planar geometry about the Pt(II) atom. The remaining L-Pt-L bond angles open in the following order (mean values): 95.9 (±5)° (S
2
-Pt-P) < 99.3 (±5)° (S
1
-Pt-P) < 162.4 (±1.0)° (S
1
-Pt-S
2
) < 174.4 (±2.2)° (B
1
-Pt-P). The Pt-L bond distance increases in the following order (mean values): 2.110 (±19) Å (Pt-B
1
) < 2.284 (±10) Å (Pt-S
2
) < 2.301 (±3) Å (Pt-S
1
) < 2.382 (±2) Å (Pt-P).